CVE-2025-13401Public exploitNetwork attack vector

Stored XSS via unescaped LCP image attributes

Published Dec 3, 2025 · Updated Apr 8, 2026

Stored XSS in Optimizing Matters Autoptimize 3.1.13 and earlier allows remote authenticated users to inject scripts through LCP image attributes. The create_img_preload_tag function converts image tags into preload links while preserving unapproved event-handler attributes such as onload. Contributor-level access is sufficient, and the stored JavaScript executes when a user opens an affected page within the same browser security context.

CVSS severity6.4
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in Optimizing Matters Autoptimize 3.1.13 and earlier allows remote authenticated users to inject scripts through LCP image attributes. The create_img_preload_tag function converts image tags into preload links while preserving unapproved event-handler attributes such as onload. Contributor-level access is sufficient, and the stored JavaScript executes when a user opens an affected page within the same browser security context.

The record

CVE
CVE-2025-13401
Published
Dec 3, 2025
Updated
Apr 8, 2026
Vendor
Optimizing Matters
Product
Autoptimize
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 3, 2025CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <=3.1.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Optimizing Matters · Autoptimizeversion=0 <=3.1.13

Published CVSS scores

6.4WordfenceCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo