CVE-2026-100237 The Wikimedia Foundation CVE debrief

Who should care

Defenders responsible for Mediawiki installations with the Thanks Extension should assess exposure and prioritize patching or workarounds. They should verify exposure and apply patches or workarounds to prevent exploitation. The vulnerability allows Stored XSS, potentially leading to unauthorized script execution or data tampering.

Why it matters

Defenders should care about CVE-2026-100237 because it allows Stored XSS in the Mediawiki - Thanks Extension, potentially leading to unauthorized script execution or data tampering. Affected deployments should verify exposure and apply patches or workarounds.

• Potential for unauthorized script execution
• Possible data tampering or theft
• Required verification of exposure and patching

Technical summary

The Mediawiki - Thanks Extension is vulnerable to Stored XSS due to improper neutralization of input during web page generation. This allows attackers to inject malicious scripts, potentially leading to unauthorized script execution or data tampering. Defenders should prioritize verifying exposure and applying patches or workarounds to prevent exploitation. The vulnerability affects Mediawiki - Thanks Extension versions before 1.43.10/1.45.5/1.46.1. Affected deployments should verify exposure and apply patches or workarounds.

Defensive priority

Defenders should prioritize verifying exposure and applying patches or workarounds to prevent exploitation.

Recommended defensive actions

• Verify exposure by checking installed versions of Mediawiki - Thanks Extension
• Apply patches or workarounds to prevent exploitation
• Monitor for suspicious activity
• 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 and NVD entry provide details on the vulnerability, but additional information on affected versions and remediation is limited. Defenders should verify exposure and apply patches or workarounds. The vulnerability allows Stored XSS, potentially leading to unauthorized script execution or data tampering. Affected deployments should prioritize patching or workarounds.

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.