Grav Vulnerable to Remote Code Execution (RCE) via Malicious Plugin ZIP Upload in Direct Install Feature

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.1 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

EPSS

• CVE-2026-42607: 4.38% estimated exploitation activity in the next 30 days; percentile 91.30 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary An authenticated user with administrative privileges can achieve Remote Code Execution (RCE) by uploading a specially crafted ZIP file through the "Direct Install" tool. While the system attempts to block direct .php file uploads, it fails to inspect the contents of uploaded ZIP archives. Once a malicious plugin is extracted, it can execute arbitrary PHP code or drop a persistent web shell on the server. Details The vulnerability exists in the handling of the directInstall task within the Admin plugin and the Grav Package Manager (GPM) core. - Vulnerable Endpoints: /admin/tools/direct-install - Vulnerable Logic: AdminController.php (lines 1247-1295) and Gpm.php (lines 214-285). - Root Cause: The function Installer::install() (called in Gpm.php:291) extracts the contents of the ZIP file directly into the /user/ plugins/ or /user/themes/ directories without validating the file extensions or the content of the files inside the archive. PoC 1. Prepare the Malicious Plugin Create…

Published by the source

5 May 2026, 21:21 UTC

Last modified by the source

13 May 2026, 13:51 UTC

Source last checked

26 Oct 2026, 14:40 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-w48r-jppp-rcfw

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# Patch Next advisory brief: CVE-2026-42607

Advisory: Grav Vulnerable to Remote Code Execution (RCE) via Malicious Plugin ZIP Upload in Direct Install Feature
IDs: CVE-2026-42607, GHSA-w48r-jppp-rcfw
Record: https://patchnext.com/advisories/cve-2026-42607 (revision 1, source checked 26 Oct 2026, 14:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: getgrav/grav 2.0.0-beta.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist getgrav/grav: affected < 2.0.0-beta.2; fixed in 2.0.0-beta.2

## Suggested inspection (read-only)
- Packagist getgrav/grav: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on getgrav/grav.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-w48r-jppp-rcfw (GitHub-reviewed advisory GHSA-w48r-jppp-rcfw lists affected ranges: Packagist getgrav/grav >=0 <2.0.0-beta.2)

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