CVE-2025-30903Network attack vector

Contributor-level script execution via reversed output escaping

Published Mar 27, 2025 · Updated Apr 28, 2026

Stored DOM-based XSS in Alex Mills SyntaxHighlighter Evolved 3.7.1 and earlier allows remote authenticated users to execute JavaScript. When a code block names an unknown language, the rendering path reverses WordPress escaping instead of preserving it, allowing attacker-controlled markup to reach the page. Contributor-level access is required to supply the crafted code block, and a visitor must view the affected page for the script to run in that visitor's browser.

CVSS severity6.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored DOM-based XSS in Alex Mills SyntaxHighlighter Evolved 3.7.1 and earlier allows remote authenticated users to execute JavaScript. When a code block names an unknown language, the rendering path reverses WordPress escaping instead of preserving it, allowing attacker-controlled markup to reach the page. Contributor-level access is required to supply the crafted code block, and a visitor must view the affected page for the script to run in that visitor's browser.

The record

CVE
CVE-2025-30903
Published
Mar 27, 2025
Updated
Apr 28, 2026
Vendor
Alex Mills
Product
SyntaxHighlighter Evolved
Classifications
CWE-79, CAPEC-588, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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 <=3.7.1 changes=[{"at":"3.7.2","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Alex Mills · SyntaxHighlighter Evolvedversion=0 <=3.7.1 changes=[{"at":"3.7.2","status":"unaffected"}]

Published CVSS scores

6.5PatchstackCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L

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')
CAPEC-588DOM-Based XSS
T1059.007Command and Scripting Interpreter: JavaScript

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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