CVE-2026-39693Network attack vector

Author-level script execution via unsanitized captions

Published Apr 8, 2026 · Updated Apr 8, 2026

Cross-site scripting in Fesomia FSM Custom Featured Image Caption 1.25.1 and earlier allows remote authenticated users to run scripts in visitors' browsers. The caption box accepted script-bearing content without WordPress sanitization, and the plugin emitted that stored content when it rendered captions. Author-level WordPress access is required to supply the caption, and another user's browser must render the affected caption for script execution.

CVSS severityUnavailable
Unscored
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Fesomia FSM Custom Featured Image Caption 1.25.1 and earlier allows remote authenticated users to run scripts in visitors' browsers. The caption box accepted script-bearing content without WordPress sanitization, and the plugin emitted that stored content when it rendered captions. Author-level WordPress access is required to supply the caption, and another user's browser must render the affected caption for script execution.

The record

CVE
CVE-2026-39693
Published
Apr 8, 2026
Updated
Apr 8, 2026
Vendor
Fesomia
Product
FSM Custom Featured Image Caption
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.25.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Fesomia · FSM Custom Featured Image Captionversion=0 <=1.25.1

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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