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

> An authenticated editor can inject JavaScript via Markdown media attributes, leading to stored XSS in Grav CMS.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 May 2026
- **Updated:** 11 May 2026
- **Also known as:** GHSA-r7fx-8g49-7hhr

## 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 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-42841?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `getgrav/grav` | Packagist | All versions | 2.0.0-beta.2 |
| `getgrav/grav` | Packagist | All versions | 2.0.0-beta.2 |

Products: Getgrav Grav.

## How do I fix CVE-2026-42841?

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

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

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42841 and fix it if it is affected.

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

Affected packages and fixed versions:
- getgrav/grav (Packagist): affected all versions; fixed in 2.0.0-beta.2
- getgrav/grav (Packagist): affected all versions; fixed in 2.0.0-beta.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42841/ (Markdown: https://insights.sbomify.com/CVE-2026-42841/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42841
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42841
- OSV: https://osv.dev/vulnerability/CVE-2026-42841

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42841/
Summaries are generated and may contain mistakes; the official description above is the record.