How severe is GHSA-vj3m-2g9h-vm4p?

No CVSS score has been assigned to GHSA-vj3m-2g9h-vm4p yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-vj3m-2g9h-vm4p?

GHSA-vj3m-2g9h-vm4p affects the following packages: getgrav/grav (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-vj3m-2g9h-vm4p?

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.

How do I detect GHSA-vj3m-2g9h-vm4p in my Packagist dependencies?

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.

How do I mitigate GHSA-vj3m-2g9h-vm4p if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is GHSA-vj3m-2g9h-vm4p actively exploited in the wild?

No public exploit code has been indexed for GHSA-vj3m-2g9h-vm4p yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-vj3m-2g9h-vm4p?

GHSA-vj3m-2g9h-vm4p has an EPSS (Exploit Prediction Scoring System) score of 2.5%, placing it in the 85th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-vj3m-2g9h-vm4p?

GHSA-vj3m-2g9h-vm4p is classified as OS Command Injection (CWE-78), Deserialization of Untrusted Data (CWE-502). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-vj3m-2g9h-vm4p published, and has it been updated?

GHSA-vj3m-2g9h-vm4p was published on May 5, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

Grav has multiple RCE vectors: unsafe unserialize (x3), command injection in git clone, SSTI blocklist bypassGHSA-vj3m-2g9h-vm4p

Fix: getgrav/grav@5a12f9b

GHSA-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.

Also known asCVE-2026-56700

Published

May 5, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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

via FIRST.org ↗

2.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs85th percentile — riskier than 85% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐘getgrav/grav

Real-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_job now carries a sibling serialized_job_hmac signed with Security::getNonceKey(). reconstructJob refuses 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 forged Job for direct RCE via Job::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 triggering unserialize.
→ system/src/Grav/Common/Session.php
InstallCommand git clone shell injection — branch, url, and path values read from user/.dependencies are now passed through escapeshellarg, 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) plus twig_array_some and twig_array_every added to cleanDangerousTwig's CALLABLE_DANGEROUS_NAMES alongside the existing twig_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 in 38685ac25.
→ 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 — new twig_array_* entries in providerCallbackFunctions.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`getgrav/grav`	all versions	2.0.0-beta.2`composer require getgrav/grav:^2.0.0-beta.2`

Detection & mitigation playbook

Open-source dependency

Detect
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
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

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 s

O3 Security · Impact-Aware SCA

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