CVE-2026-34577

High

Description

Postiz is an AI social media scheduling tool. Prior to version 2.21.3, the GET /public/stream endpoint in PublicController accepts a user-supplied url query parameter and proxies the full HTTP response back to the caller. The only validation is url.endsWith('mp4'), which is trivially bypassable by appending .mp4 as a query parameter value or URL fragment. The endpoint requires no authentication and has no SSRF protections, allowing an unauthenticated attacker to read responses from internal services, cloud metadata endpoints, and other network-internal resources. This issue has been patched in version 2.21.3.

SeverityHigh
CVSS8.6
Exploit probability—
ProductGitroom Postiz
PublishedApr 2, 2026
First seenApr 2, 2026

How to fix

Update
  • gitroom postiz2.21.3 or later

Affected products

ProductAffected versionsFixed in
gitroom postizv < 2.21.32.21.3

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