CVE-2026-58031 Wikimedia Foundation CVE debrief

Who should care

Users of MediaWiki, especially those hosting it, should be aware of this vulnerability and take steps to mitigate it. This includes updating MediaWiki to version 1.46.0 or later, reviewing and adjusting input validation and sanitization in affected versions, and monitoring for suspicious activity related to the ApiSandboxLayout component.

Technical summary

The vulnerability is located in the resources/src/mediawiki.Special.Apisandbox/ApiSandboxLayout.Js file. It allows for Cross-site Scripting (XSS) attacks when user input is not properly neutralized during web page generation. The issue affects MediaWiki from version 1.46.0-rc.0 before 1.46.0. The vulnerability has a medium priority due to the potential for user interaction and exploitation. Users of MediaWiki, especially those hosting it, should be aware of this vulnerability and take steps to mitigate it by updating to version 1.46.0 or later, reviewing and adjusting input validation and sanitization in affected versions, and monitoring for suspicious activity related to the ApiSandboxLayout component. This includes reviewing compensating controls for exposed systems while remediation is scheduled and verified, checking relevant monitoring, detection, and logs for exposed assets that need extra review, and tracking exceptions, retesting remediated assets, and closing the item only after evidence is documented.

Defensive priority

Medium priority due to the potential for user interaction and exploitation.

Recommended defensive actions

• Update MediaWiki to version 1.46.0 or later
• Review and adjust input validation and sanitization in affected versions
• Monitor for suspicious activity related to the ApiSandboxLayout component
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-01T15:17:11.020Z and was last modified on 2026-07-09T17:21:35.417Z. The NVD entry is currently Analyzed. This information is based on the supplied source corpus and may not reflect the full scope of the vulnerability. Users should verify the details with the official CVE record and NVD entry for the most accurate information. The evidence provided is limited, and defenders should be cautious when assessing the vulnerability.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.