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TI-2026-26825 Aliases CVE-2026-34577

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

Priority HIGH 76CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-918 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00482 41st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed postiz-app (gitroomhq): 2.21.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
gitroomhqpostiz-appbefore 2.21.32.21.3Patch availableCNA
  • postiz-app Vendorgitroomhq Affected before 2.21.3 Fixed in 2.21.3 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:gitroom:postiz:*:*:*:*:*:*:*:*before 2.21.3Vulnerablegitroomhq
  • cpe:2.3:a:gitroom:postiz:*:*:*:*:*:*:*:* Versions before 2.21.3 Vulnerable ·gitroomhq

Remediation

  • Fix · CNA postiz-app (gitroomhq) Fixed in 2.21.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34577

References

  • TI-2026-28982 Postiz has Server-Side Request Forgery via Redirect Bypass in /api/public/stream CVSS 3.1HIGH 8.2
  • TI-2026-29238 Postiz Has Unrestricted File Upload via MIME Type Spoofing that Leads to Stored XSS CVSS 3.1CRITICAL 9.0
  • TI-2026-26824 Postiz: SSRF in upload-from-url endpoint allows fetching internal resources and cloud metadata CVSS 4.0HIGH 8.3
  • TI-2026-26837 Postiz: SSRF via Webhook Creation Endpoint Missing URL Safety Validation CVSS 3.1MEDIUM 5.4
  • TI-2026-30607 Postiz: Arbitrary Code Execution and Token Exfiltration in pr-docker-build.yml via untrusted Dockerfile.dev CVSS 3.1CRITICAL 10.0
  • TI-2026-30836 Postiz stored XSS in public preview page CVSS 3.1CRITICAL 9.0

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences