Cross-Site Scripting (XSS) in Joomla (CVE-2026-90906)
Summary
Cross-site scripting in Joomla (CVE-2026-90906). Confidential information can be exposed externally.
Original description
The description as published by the source.
Joomla! Core - [20260901] - XSS in HTMLHelper::link method in Joomla 1.5.0-5.4.8, 6.0.0-6.1.3 - Lack of escaping leads to XSS vulnerabilities in the link method of the HTML Helper.
Source: NIST National Vulnerability Database NVD GitHub Advisory
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-2026-90906 has been found in Joomla.
Confidential information can be exposed externally. CVSS score: 8.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Joomla CVE-2026-90906" on the vendor's site.
CVE-2026-90906 (Joomla) — CWE-79 / CVSS v3 8.3
Attack vector: remote (network-reachable)
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.
Cross-site scripting (XSS) (CWE-79) exists in Joomla.
Check the vendor advisory for the affected versions of Joomla.
Severity: High (CVSS 8.3/10). Confidential information can be exposed externally.
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. Run grep -r 'Joomla' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Joomla' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Joomlaを grep し、稼働しているサービス・バージョンを把握する。 -
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
- web developer.joomla.org
- web security@joomla.org
- web nvd.nist.gov
- web joomla.org
- web github.com