CVE-2026-42556

9.0 criticalEPSS 0.3%

Critical (9.0) in gitroom postiz. EPSS 0.3% chance of exploitation in the next 30 days.

Postiz is an AI social media scheduling tool. From version 2.21.6 to before version 2.21.7, any authenticated user who can create a post can store arbitrary HTML in post content by tampering their own save request and send the public preview link /p/<postId>?share=true to another user. The preview page renders that stored HTML with dangerouslySetInnerHTML on the main application origin. This issue has been patched in version 2.21.7.

Severity

CVSS 3.1

9.0 critical

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

EPSS: 0.3% chance of exploitation in the next 30 days; higher than 17% of CVEs (scores of 2026-10-31)
CWE: CWE-79
Published: 2026-05-08
Modified: 2026-07-24
Record from: the NVD, synced 2026-10-19

Affected

gitroom:postiz

References

https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.7
https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-hhxq-3wg7-4rj8

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