CVE-2026-58030 SyntaxHighlight stored XSS via unsanitized 'linelinks' attribute

Medium 5.3 Published 1 Jul 2026 Updated 1 Jul 2026

Attackers can inject malicious scripts via the linelinks attribute in SyntaxHighlight_GeSHi, potentially compromising user sessions.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-58030?

CVE-2026-58030 is a medium-severity cross-site scripting vulnerability in Mediawiki Mediawiki, published on 1 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation SyntaxHighlight_GeSHi.

This vulnerability is associated with program files includes/SyntaxHighlight.Php.

This issue affects SyntaxHighlight_GeSHi: from * before 1.46.0, 1.45.4, 1.44.6, 1.43.9.

Weakness: CWE-79

Which versions are affected by CVE-2026-58030?

It affects 1 product.

Products include Mediawiki Mediawiki.

How do I fix CVE-2026-58030?

Upgrade to a fixed version.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-58030 being exploited?

There is no known exploitation of CVE-2026-58030 in the wild and no public exploit code.

All Mediawiki Mediawiki vulnerabilities

Sources

Also known as DEBIAN-CVE-2026-58030, GHSA-vmx6-3fp5-595p, MINI-4jpf-gmh6-m6h2, MINI-g957-7gvg-78r5, MINI-vm9h-23j5-6qjg, UBUNTU-CVE-2026-58030.