CVE-2026-42841 Grav: Stored XSS via Markdown media attribute() action in Grav CMS

What is CVE-2026-42841?

CVE-2026-42841 is a medium-severity cross-site scripting vulnerability in Getgrav Grav, published on 11 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, an authenticated user with page editing permissions can inject an executable JavaScript event-handler attribute into rendered image HTML through Grav's Markdown media action syntax. The issue is caused by Markdown image query parameters being converted into callable media actions. The public attribute() media method can be reached this way, allowing an editor to set an arbitrary HTML attribute name and value on the generated image element. This vulnerability is fixed in 2.0.0-beta.2.

Weakness: CWE-79

Which versions are affected by CVE-2026-42841?

2 open source packages ship an affected version, including getgrav/grav. It affects 1 product.

Products include Getgrav Grav.

How do I fix CVE-2026-42841?

Upgrade getgrav/grav to 2.0.0-beta.2 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-42841 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42841 exists.

Other vulnerabilities in Getgrav Grav

• CVE-2023-34251 Grav Server Side Template Injection vulnerability Critical 10.0
• CVE-2025-46199 Cross-site scripting in n/a Critical 9.8
• CVE-2021-47812 GravCMS 1.10.7 - Arbitrary YAML Write/Update (Unauthenticated) (2) Critical 9.3
• CVE-2025-66844 Grav may be vulnerable to SSRF attack via Twig Templates Critical 9.1
• CVE-2022-2073 Code Injection in getgrav/grav Critical 9.1

All Getgrav Grav vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-r7fx-8g49-7hhr.