CVE-2026-100377 Wikimedia Foundation CVE debrief

Who should care

Defenders responsible for Mediawiki - WikiLambda Extension deployments should assess exposure and verify remediation status. They should also prioritize verifying the remediation status and assessing exposure for Mediawiki - WikiLambda Extension version 1.47.0-alpha. Additionally, operators, platforms, vulnerability-management teams, and security teams may be impacted by this vulnerability and should take necessary actions.

Why it matters

CVE-2026-100377 is a medium-severity vulnerability in Mediawiki - WikiLambda Extension that requires verification of remediation status and exposure assessment.

• Verify remediation status for Mediawiki - WikiLambda Extension version 1.47.0-alpha
• Assess exposure for Mediawiki - WikiLambda Extension version 1.47.0-alpha
• Monitor for potential sensitive information exposure

Technical summary

The Mediawiki - WikiLambda Extension version 1.47.0-alpha is vulnerable to Exposure of Sensitive Information to an Unauthorized Actor. The issue has been remediated on the `master` branch. The vulnerability allows unauthorized actors to access sensitive information. Defenders should prioritize verifying the remediation status and assessing exposure for Mediawiki - WikiLambda Extension version 1.47.0-alpha. The issue has a medium severity and requires verification of remediation status and exposure assessment. The affected product context and defensive impact should be considered when assessing the vulnerability.

Defensive priority

Defenders should prioritize verifying the remediation status and assessing exposure for Mediawiki - WikiLambda Extension version 1.47.0-alpha.

Recommended defensive actions

• Verify the remediation status of Mediawiki - WikiLambda Extension version 1.47.0-alpha
• Assess exposure for Mediawiki - WikiLambda Extension version 1.47.0-alpha
• Monitor for potential sensitive information exposure
• 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 limited information about the vulnerability. Further verification is required to determine the actual impact and affected scope. The CVE record was published on 2026-09-25T21:17:21.650Z and has not been modified since then. The official CVE Program record and NVD detail page provide source-provided CVE metadata and source-specific vulnerability assessment. However, additional information from other sources is needed to fully understand 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.