Postiz: Unauthenticated Full-Read SSRF via /public/stream Endpoint with Trivially Bypassable Extension Check
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
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
Remediation
- Fix · CNA postiz-app (gitroomhq) Fixed in 2.21.3
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34577
References
More gitroomhq Postiz vulnerabilities
- 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