Cloudanix VulnDB

GHSA-vj3m-2g9h-vm4p

None

Grav has multiple RCE vectors: unsafe unserialize (x3), command injection in git clone, SSTI blocklist bypass

CVSS

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EPSS

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Published

May 5, 2026

CISA due date

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The record

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 ---

Affected packages

Ecosystem Package Introduced Fixed

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