CVE-2026-56700

Description

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.

Severity (CVSS)

Weaknesses

• CWE-78 — Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
• CWE-502 — Deserialization of Untrusted Data

Affected products

References

• https://github.com/getgrav/grav/security/advisories/GHSA-vj3m-2g9h-vm4p (vendor-advisory)
• https://www.vulncheck.com/advisories/grav-multiple-remote-code-execution-vulnerabilities-via-unsafe-unserialize-and-command-injection (third-party-advisory)