OS Command Injection in Grav CMS (CVE-2026-56700)
Summary
OS command injection in Grav CMS (CVE-2026-56700). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 2.0.0-beta.2 or later.
Original description
The description as published by the source.
Grav CMS before 2.0.0-beta.2 contains multiple code-execution vulnerabilities. Three unsafe unserialize() calls - in Scheduler\JobQueue, Framework\Cache\Adapter\FileCache, and Session - deserialize untrusted data without restricting allowed classes, enabling PHP object injection and, via a gadget chain, arbitrary code execution where an attacker controls the serialized input. Additionally, InstallCommand's git clone operation passes the branch, url, and path parameters into a shell command without escaping, allowing OS command injection via plugin/theme installation (which requires admin access). A Twig security blocklist bypass (server-side template injection) is also present. The issues are fixed in 2.0.0-beta.2.
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-2026-56700 has been found in Grav CMS.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: upgrade Grav CMS to 2.0.0-beta.2 or later.
If unsure, ask your IT team or search "Grav CMS CVE-2026-56700" on the vendor's site.
CVE-2026-56700 (Grav CMS) — CWE-78 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 2.0.0-beta.2 — 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.
OS command injection (CWE-78) exists in Grav CMS.
Check the vendor advisory for the affected versions of Grav CMS.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to 2.0.0-beta.2.
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 CMS 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 CMS to 2.0.0-beta.2ステージング環境で 2.0.0-beta.2 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
- advisory github.com
- advisory nvd.nist.gov
- advisory vulncheck.com
- advisory github.com
- web github.com