UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-04986

Franklin Investors Securities Trust

(Exact name of registrant as specified in charter)

One Franklin Parkway, San Mateo, CA 94403-1906

(Address of principal executive offices) (Zip code)

Alison Baur

Franklin Templeton

One Franklin Parkway,

San Mateo, CA 94403-1906

(Name and address of agent for service)

Registrant’s telephone number, including area code: (650) 312-2000

Date of fiscal year end: October 31

Date of reporting period: April 30, 2026

(a) The Report to Shareholders is filed herewith

Franklin Convertible Securities Fund
Class A   [FISCX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Convertible Securities Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class A	$42	0.83%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$2,954,299,347
Total Number of Portfolio Holdings	74
Portfolio Turnover Rate	5.54%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Convertible Securities Fund
Class C   [FROTX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Convertible Securities Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class C	$80	1.57%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$2,954,299,347
Total Number of Portfolio Holdings	74
Portfolio Turnover Rate	5.54%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Convertible Securities Fund
Class R6   [FCSKX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Convertible Securities Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class R6	$26	0.50%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$2,954,299,347
Total Number of Portfolio Holdings	74
Portfolio Turnover Rate	5.54%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Convertible Securities Fund
Advisor Class   [FCSZX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Convertible Securities Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Advisor Class	$30	0.58%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$2,954,299,347
Total Number of Portfolio Holdings	74
Portfolio Turnover Rate	5.54%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Equity Income Fund
Class A   [FISEX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Equity Income Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class A	$42	0.81%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$4,826,532,503
Total Number of Portfolio Holdings	89
Portfolio Turnover Rate	23.36%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Equity Income Fund
Class C   [FRETX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Equity Income Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class C	$81	1.56%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$4,826,532,503
Total Number of Portfolio Holdings	89
Portfolio Turnover Rate	23.36%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Equity Income Fund
Class R   [FREIX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Equity Income Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class R	$55	1.06%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$4,826,532,503
Total Number of Portfolio Holdings	89
Portfolio Turnover Rate	23.36%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Equity Income Fund
Class R6   [FEIQX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Equity Income Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class R6	$26	0.50%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$4,826,532,503
Total Number of Portfolio Holdings	89
Portfolio Turnover Rate	23.36%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Equity Income Fund
Advisor Class   [FEIFX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Equity Income Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Advisor Class	$29	0.56%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$4,826,532,503
Total Number of Portfolio Holdings	89
Portfolio Turnover Rate	23.36%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^* (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Floating Rate Daily Access Fund
Class A   [FAFRX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Floating Rate Daily Access Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class A	$47	0.95%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,194,366,972
Total Number of Portfolio Holdings	273
Portfolio Turnover Rate	13.94%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Floating Rate Daily Access Fund
Class C   [FCFRX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Floating Rate Daily Access Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class C	$67	1.35%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,194,366,972
Total Number of Portfolio Holdings	273
Portfolio Turnover Rate	13.94%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Floating Rate Daily Access Fund
Class R6   [FFRDX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Floating Rate Daily Access Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class R6	$31	0.62%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,194,366,972
Total Number of Portfolio Holdings	273
Portfolio Turnover Rate	13.94%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Floating Rate Daily Access Fund
Advisor Class   [FDAAX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Floating Rate Daily Access Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Advisor Class	$35	0.70%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,194,366,972
Total Number of Portfolio Holdings	273
Portfolio Turnover Rate	13.94%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Long Duration Credit Fund
Class R6   [FLDBX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Long Duration Credit Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class R6	$15	0.30%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$62,174,186
Total Number of Portfolio Holdings	352
Portfolio Turnover Rate	27%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*  (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Low Duration Total Return Fund
Class A   [FLDAX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Low Duration Total Return Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class A	$33	0.66%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,857,826,709
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)	769
Portfolio Turnover Rate	33.73%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Low Duration Total Return Fund
Class C   [FLDCX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Low Duration Total Return Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class C	$53	1.07%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,857,826,709
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)	769
Portfolio Turnover Rate	33.73%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Low Duration Total Return Fund
Class R   [FLDRX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Low Duration Total Return Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class R	$45	0.91%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,857,826,709
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)	769
Portfolio Turnover Rate	33.73%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)

	WHERE CAN I FIND ADDITIONAL INFORMATION ABOUT THE FUND?
	Additional information is available on https://www.franklintempleton.com/regulatory-fund-documents, including its:
	• prospectus • proxy voting information • financial information • holdings • tax information

Franklin Low Duration Total Return Fund
Class R6   [FLRRX]
Semi-Annual Shareholder Report | April 30, 2026

This semi-annual shareholder report contains important information about Franklin Low Duration Total Return Fund for the period November 1, 2025, to April 30, 2026.
You can find additional information about the Fund at https://www.franklintempleton.com/regulatory-fund-documents. You can also request this information by contacting us at (800) DIAL BEN/342-5236.  

WHAT WERE THE FUND COSTS FOR THE LAST SIX MONTHS? (based on a hypothetical $10,000 investment)

Class Name	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment*,†
Class R6	$15	0.30%

*	Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

†	Annualized.

KEY FUND STATISTICS (as of April 30, 2026)

Total Net Assets	$1,857,826,709
Total Number of Portfolio Holdings (excludes derivatives, except purchased options, if any)	769
Portfolio Turnover Rate	33.73%

WHAT DID THE FUND INVEST IN? (as of April 30, 2026)

Portfolio Composition^*,† (% of Total Investments)