Privilege Escalation in Grav Login plugin (CVE-2026-65603)
Summary
Vulnerability in Grav Login plugin (CVE-2026-65603). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 3.8.12 or later.
Original description
The description as published by the source.
The Grav Login plugin (grav-plugin-login) versions <= 3.8.11 contain a privilege escalation flaw in the authenticated profile self-update handler (processUserProfile(), the update_user task). Unlike the registration handler, this handler does not strip privilege fields ('groups','access') from user-submitted form data before persisting them. When an administrator has added 'groups' and/or 'access' to plugins.login.user_registration.fields and the default 'regular'/DataUser account backend is in use, a low-privilege authenticated user can POST crafted profile form data (e.g. access[admin][super]=true) to escalate to super-admin, enabling admin panel access, scheduler abuse (RCE), and Twig evaluation. Fixed in 3.8.12.
Source: GitHub Security Advisories (Global) 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-2026-65603 has been found in Grav Login plugin.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade Grav Login plugin to 3.8.12 or later.
If unsure, ask your IT team or search "Grav Login plugin CVE-2026-65603" on the vendor's site.
CVE-2026-65603 (Grav Login plugin) — CWE-269 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Patched: 3.8.12 — apply immediately
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-269) exists in Grav Login plugin.
Check the vendor advisory for the affected versions of Grav Login plugin.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to 3.8.12.
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 Grav Login plugin 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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2Apply patch patch
Upgrade Grav Login plugin to 3.8.12ステージング環境で 3.8.12 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-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 github.com
- web nvd.nist.gov
- web disclosure@vulncheck.com
- web github.com