CVE-2026-42346: CWE-918: Server-Side Request Forgery (SSRF) in gitroomhq postiz-app
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.
AI Analysis
Technical Summary
Postiz versions 2.16.6 through 2.21.6 contain a Server-Side Request Forgery vulnerability due to a TOCTOU race condition in the SSRF protections. The function isSafePublicHttpsUrl() performs DNS resolution to validate the target IP, but the subsequent fetch() call independently resolves DNS again. This discrepancy allows an attacker who controls DNS responses to perform DNS rebinding attacks, redirecting server requests to internal network addresses that should be protected. The vulnerability is tracked as CWE-918 and has a CVSS 3.1 score of 6.5 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N). The issue is resolved in Postiz version 2.21.7.
Potential Impact
Successful exploitation could allow an unauthenticated attacker to cause the Postiz server to make unauthorized requests to internal network resources, potentially exposing sensitive information (high confidentiality impact). Integrity impact is limited, and availability is not affected. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade Postiz to version 2.21.7 or later, where this SSRF vulnerability has been patched. Since the vendor advisory confirms the fix in 2.21.7, applying this official update is the recommended remediation. Patch status is confirmed by the vendor's versioning information in the description.
CVE-2026-42346: CWE-918: Server-Side Request Forgery (SSRF) in gitroomhq postiz-app
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Postiz versions 2.16.6 through 2.21.6 contain a Server-Side Request Forgery vulnerability due to a TOCTOU race condition in the SSRF protections. The function isSafePublicHttpsUrl() performs DNS resolution to validate the target IP, but the subsequent fetch() call independently resolves DNS again. This discrepancy allows an attacker who controls DNS responses to perform DNS rebinding attacks, redirecting server requests to internal network addresses that should be protected. The vulnerability is tracked as CWE-918 and has a CVSS 3.1 score of 6.5 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N). The issue is resolved in Postiz version 2.21.7.
Potential Impact
Successful exploitation could allow an unauthenticated attacker to cause the Postiz server to make unauthorized requests to internal network resources, potentially exposing sensitive information (high confidentiality impact). Integrity impact is limited, and availability is not affected. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade Postiz to version 2.21.7 or later, where this SSRF vulnerability has been patched. Since the vendor advisory confirms the fix in 2.21.7, applying this official update is the recommended remediation. Patch status is confirmed by the vendor's versioning information in the description.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-26T13:26:14.515Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69fe68edcbff5d861039d874
Added to database: 5/8/2026, 10:51:25 PM
Last enriched: 5/8/2026, 11:07:25 PM
Last updated: 5/9/2026, 2:25:53 AM
Views: 7
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