Grav Vulnerable to Publisher-Level Stored XSS via Unquoted Event Attributes

Exploitation

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

CVSS

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

EPSS

• CVE-2026-42612: 0.24% estimated exploitation activity in the next 30 days; percentile 14.88 (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 A stored Cross-Site Scripting (XSS) vulnerability in getgrav/grav allows publisher-level accounts to execute arbitrary JavaScript. The issue arises from a blacklist bypass in the detectXss() function when handling unquoted HTML event attributes. Details The detectXss() function relies on a blacklist pattern to filter malicious attributes. The specific regex pattern used to match on events is flawed: This pattern fails to properly identify on event handlers that are constructed without quotation marks. This allows an attacker to completely bypass the filter. Note: It is highly recommended to replace this blacklist approach with a robust, established HTML sanitization library. PoC An attacker with publisher-level access can reproduce this by injecting the following payload into any vulnerable content field: <img width="1889" height="482" alt="image1" src="https://github.com/user-attachments/assets/0f1a339b-25a8-4b6e-91af-8c59e6a39297" / <img width="3055" height="920"…

Published by the source

5 May 2026, 21:27 UTC

Last modified by the source

13 May 2026, 13:52 UTC

Source last checked

26 Oct 2026, 14:40 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9695-8fr9-hw5q

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-42612

Advisory: Grav Vulnerable to Publisher-Level Stored XSS via Unquoted Event Attributes
IDs: CVE-2026-42612, GHSA-9695-8fr9-hw5q
Record: https://patchnext.com/advisories/cve-2026-42612 (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: High (CVSS 8.5)
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-9695-8fr9-hw5q (GitHub-reviewed advisory GHSA-9695-8fr9-hw5q lists affected ranges: Packagist getgrav/grav >=0 <2.0.0-beta.2)

Commands are suggestions: review each one before running it.