Cross-Site Scripting (XSS) in GetSimpleCMS Community Edition (CVE-2026-26351)
Summary
Cross-site scripting in GetSimpleCMS Community Edition (CVE-2026-26351). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
GetSimpleCMS Community Edition (CE) version 3.3.16 contains a stored cross-site scripting (XSS) vulnerability in the Theme to Components functionality within components.php. User-supplied input provided to the "slug" field of a component is stored without proper output encoding. While other fields are sanitized using safe_slash_html(), the slug parameter is written to XML and later rendered in the administrative interface without sanitation, resulting in persistent execution of arbitrary JavaScript. An authenticated administrator can inject malicious script content that executes whenever the affected Components page is viewed by any authenticated user, enabling session hijacking, unauthorized administrative actions, and persistent compromise of the CMS administrative interface.
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-2026-26351 has been found in GetSimpleCMS Community Edition.
Risk of unauthorized operations or information disclosure. CVSS score: 4.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "GetSimpleCMS Community Edition CVE-2026-26351" on the vendor's site.
CVE-2026-26351 (GetSimpleCMS Community Edition) — CWE-79 / CVSS v3 4.8
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 GetSimpleCMS Community Edition.
Check the vendor advisory for the affected versions of GetSimpleCMS Community Edition.
Severity: Medium (CVSS 4.8/10). 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
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで GetSimpleCMS Community Edition を使っているサービスとバージョンを洗い出す。
-
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
- advisory disclosure@vulncheck.com
- web disclosure@vulncheck.com
- web disclosure@vulncheck.com
- web disclosure@vulncheck.com