Postiz is an AI social media scheduling tool. From version 2.16.6 to before version 2.21.7, all SSRF protections added in v2.21.4–v2.21.6 share a fundamental TOCTOU (Time-of-Check-Time-of-Use) vulnerability: isSafePublicHttpsUrl() resolves DNS to validate the target IP, but subsequent fetch() calls resolve DNS independently. An attacker controlling a DNS server can exploit this gap via DNS rebinding to redirect requests to internal network addresses. This issue has been patched in version 2.21.7.
History

Fri, 08 May 2026 23:45:00 +0000

Type Values Removed Values Added
First Time appeared Gitroomhq
Gitroomhq postiz-app
Vendors & Products Gitroomhq
Gitroomhq postiz-app

Fri, 08 May 2026 22:45:00 +0000

Type Values Removed Values Added
Description Postiz is an AI social media scheduling tool. From version 2.16.6 to before version 2.21.7, all SSRF protections added in v2.21.4–v2.21.6 share a fundamental TOCTOU (Time-of-Check-Time-of-Use) vulnerability: isSafePublicHttpsUrl() resolves DNS to validate the target IP, but subsequent fetch() calls resolve DNS independently. An attacker controlling a DNS server can exploit this gap via DNS rebinding to redirect requests to internal network addresses. This issue has been patched in version 2.21.7.
Title Postiz: TOCTOU DNS rebinding bypasses all SSRF URL validation paths
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-08T22:26:50.501Z

Reserved: 2026-04-26T13:26:14.515Z

Link: CVE-2026-42346

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-08T23:16:37.903

Modified: 2026-05-08T23:16:37.903

Link: CVE-2026-42346

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-09T00:00:25Z