CVE-2026-58655
The bundled Grav Flex Objects plugin (getgrav/grav-plugin-flex-objects) before 1.4.0 contains a stored server-side template injection vulnerability. When rendering dynamic collection or object titles, the plugin passes user-controlled frontmatter values (page.header.flex.collection.title or page.header.flex.object.title) to Twig's template_from_string(), causing them to be evaluated as Twig code rather than treated as text. This path bypasses Grav's Security::cleanDangerousTwig() sanitization. An attacker who can control the title frontmatter of a publicly reachable Flex Objects page can achieve arbitrary Twig execution and escalate to remote command execution via access to internal Grav services such as the scheduler.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 4.0 : 8.7 HIGH · CVSS 3.1 : 8.8 HIGH
Vector: AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.