CVE-2026-58031 Stored i18n XSS in Special:ApiSandbox when a deprecated module is selected
Stored XSS in MediaWiki's API Sandbox allows attackers to execute scripts when a deprecated module is selected, risking user session hijacking.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-58031?
CVE-2026-58031 is a cross-site scripting vulnerability in Mediawiki Mediawiki, published on 1 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation MediaWiki.
This vulnerability is associated with program files resources/src/mediawiki.Special.Apisandbox/ApiSandboxLayout.Js.
This issue affects MediaWiki: from 1.46.0-rc.0 before 1.46.0.
Weakness: CWE-79
Which versions are affected by CVE-2026-58031?
It affects 1 product.
Products include Mediawiki Mediawiki.
How do I fix CVE-2026-58031?
No fix has been published for CVE-2026-58031 yet. Limit exposure of the affected software until one is available.
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-2026-58031 being exploited?
There is no known exploitation of CVE-2026-58031 in the wild and no public exploit code.
Other vulnerabilities in Mediawiki Mediawiki
Sources
Also known as GHSA-f942-cxv6-p9mx, UBUNTU-CVE-2026-58031.