RCE in Grav
CVE-2026-56700
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.
Vulnerability class: Command Injection (OS Command Injection)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.025 (84.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 84.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.025 · newest: 0.025 · change: 0.000
Affected products
- Grav — versions 0, 2.0.0-beta.2
Weakness classification (CWE)
References
- github.com/getgrav/grav/security/advisories/GHSA-vj3m-2g9h-vm4p (vendor-advisory)
- www.vulncheck.com/advisories/grav-multiple-remote-code-execution-vulnerabilitie… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56700?
- CVE-2026-56700 is a critical-severity vulnerability in Grav, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-06-30.
- How severe is CVE-2026-56700?
- Critical severity. CVSS v3 base score is 9.8 out of 10.