GHSA-vj3m-2g9h-vm4p — getgrav/grav
Fix: getgrav/grav@5a12f9bGHSA-vj3m-2g9h-vm4p is a OS Command Injection vulnerability in getgrav/grav. A fix is available for getgrav/grav — see the affected versions and patch details below.
Grav has multiple RCE vectors: unsafe unserialize (x3), command injection in git clone, SSTI blocklist bypass
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-vj3m-2g9h-vm4p.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
getgrav/gravReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Multiple RCE vectors were found in Grav CMS. Three are critical, two are high.
1. Unsafe unserialize() in JobQueue — direct RCE gadget (Critical)
system/src/Grav/Common/Scheduler/JobQueue.php:465 calls unserialize(base64_decode(...)) without restricting allowed_classes. The Job class has call_user_func_array($this->command, $this->args) in its execution path, which is a direct gadget chain — inject a serialized Job with command = 'system' and args = ['whoami'].
The same codebase actually has a Serializable trait that correctly restricts classes, so this inconsistency stands out.
2. Unsafe unserialize() in FileCache — arbitrary class instantiation (Critical)
system/src/Grav/Framework/Cache/Adapter/FileCache.php:75 does unserialize($value, ['allowed_classes' => true]). That true allows instantiation of any class. If an attacker can write to the cache directory (via any file write primitive), they get object injection → RCE.
3. Unsafe unserialize() in Session (High)
system/src/Grav/Common/Session.php:116 — same allowed_classes => true pattern on session data. Lower severity since session storage is typically more restricted.
4. Command injection in git clone (Critical)
system/src/Grav/Console/Cli/InstallCommand.php:150 — only $this->destination uses escapeshellarg(). The $data['branch'], $data['url'], and $data['path'] variables go directly into the shell command without escaping. Admin-accessible via plugin/theme installation.
5. SSTI blocklist bypass (High)
system/src/Grav/Common/Security.php:267-286 — cleanDangerousTwig() blocks twig_array_map and twig_array_filter but not twig_array_reduce. Also missing file_get_contents and fwrite from the dangerous function blocklist. An attacker who can inject Twig templates can bypass the security filter.
All five are independently exploitable. The unserialize issues are the most concerning since they don't require admin access if there's any file write primitive.
— ProScan AppSec | proscan.one
Maintainer note — fix applied (2026-04-24)
Fixed in Grav core on the 2.0 branch: commit c66dfeb5f (items #1, #2, #3, #4) and commit 38685ac25 + c66dfeb5f (item #5) — ships in 2.0.0-beta.2.
All five vectors addressed:
-
Scheduler\JobQueue unsafe unserialize —
serialized_jobnow carries a siblingserialized_job_hmacsigned withSecurity::getNonceKey().reconstructJobrefuses to unserialize an item whose HMAC is missing/mismatched and falls through to the safe structured-fields rebuild. A tampered queue file can no longer smuggle a forgedJobfor direct RCE viaJob::exec → call_user_func_array.
→system/src/Grav/Common/Scheduler/JobQueue.php -
FileCache unsafe unserialize — same HMAC-integrity approach; see separate GHSA-gwfr-jfjf-92vv.
→system/src/Grav/Framework/Cache/Adapter/FileCache.php -
Session::getFlashObject unsafe unserialize — payload now wrapped in a
v2|<hmac>|<serialized>envelope; legacy/forged envelopes return null instead of triggeringunserialize.
→system/src/Grav/Common/Session.php -
InstallCommand
git cloneshell injection —branch,url, andpathvalues read fromuser/.dependenciesare now passed throughescapeshellarg, with a--separator before url/path to block option-injection (e.g.--upload-pack=evil).
→system/src/Grav/Console/Cli/InstallCommand.php -
SSTI blocklist bypass —
twig_array_reduce(the specific name called out) plustwig_array_someandtwig_array_everyadded tocleanDangerousTwig'sCALLABLE_DANGEROUS_NAMESalongside the existingtwig_array_map/filter. More importantly, the new Twig content sandbox in 2.0.0-beta.2 blocks this class of attack at a different layer — see the sandbox work in38685ac25.
→system/src/Grav/Common/Security.php
Tests:
tests/unit/Grav/Common/Security/UnserializeIntegritySecurityTest.php— 8 cases covering JobQueue + Session HMAC integrity.tests/unit/Grav/Common/Security/FileCacheSecurityTest.php.tests/unit/Grav/Common/Security/CleanDangerousTwigTest.php— newtwig_array_*entries inproviderCallbackFunctions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getgrav/grav | all versions | 2.0.0-beta.2composer require getgrav/grav:^2.0.0-beta.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getgrav/grav, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update getgrav/grav to 2.0.0-beta.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vj3m-2g9h-vm4p is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-vj3m-2g9h-vm4p can be triaged on real exposure rather than presence alone.
Tailored to GHSA-vj3m-2g9h-vm4p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-vj3m-2g9h-vm4p in your dependencies?
O3 Security finds GHSA-vj3m-2g9h-vm4p across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.