Vulnerability in Mediawiki - Cargo Extension (CVE-2026-39839)
Summary
Vulnerability in Mediawiki - Cargo Extension (CVE-2026-39839). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
Improper neutralization of Script-Related HTML tags in a web page (basic XSS) vulnerability in Wikimedia Foundation Mediawiki - Cargo Extension allows Stored XSS.This issue affects Mediawiki - Cargo Extension: before 3.8.7.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-39839 has been found in Mediawiki - Cargo Extension.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Mediawiki - Cargo Extension CVE-2026-39839" on the vendor's site.
CVE-2026-39839 (Mediawiki - Cargo Extension) — CWE-80 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-80) exists in Mediawiki - Cargo Extension.
Check the vendor advisory for the affected versions of Mediawiki - Cargo Extension.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Mediawiki - Cargo Extension を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- exploit phabricator.wikimedia.org
- patch gerrit.wikimedia.org
- patch gerrit.wikimedia.org