Postiz: Unauthenticated Full-Read SSRF via /public/stream Endpoint with Trivially Bypassable Extension Check

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.

Scores

EPSS (exploitation in 30 days)

0.48% · top 58% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: poc · Automatable: yes · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.6.

Weakness

• CWE-918: Server-Side Request Forgery (SSRF) (opens in a new tab)All about CWE-918 and its CVEs

Affected products

• gitroomhq · postiz-app

  • affected < 2.21.3

References (2)

• https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-mv6h-v3jg-g539 (opens in a new tab)x_refsource_CONFIRM
• https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.3 (opens in a new tab)x_refsource_MISC

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-34577](https://trackcve.app/badge/CVE-2026-34577.svg)](https://trackcve.app/cve/CVE-2026-34577)

Record last updated 3 Apr 2026, 15:52 UTC.