{"id":"CVE-2026-42346","aliases":["EUVD-2026-28856","GHSA-f7jj-p389-4w45"],"status":"published","title":"Postiz: TOCTOU DNS rebinding bypasses all SSRF URL validation paths","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.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00224,"percentile":0.13156,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-918"],"published":"2026-05-08T22:26:50Z","modified":"2026-10-28T02:30:33Z","products":[{"vendor":"gitroomhq","product":"postiz-app"}],"references":[{"url":"https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-f7jj-p389-4w45","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/gitroomhq/postiz-app/commit/071143dcb01cdeb9d5d7019892f4c6ff7b19dbeb","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.7","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42346.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42346","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-42346","title":"Postiz: TOCTOU DNS rebinding bypasses all SSRF URL validation paths","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.","status":"published","published":"2026-05-08T22:26:50.501Z","modified":"2026-05-11T14:35:55.041Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T13:40:23.731501Z"}],"euvd":[{"id":"EUVD-2026-28856","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.","status":"published","published":"2026-05-08T22:26:50Z","modified":"2026-05-11T14:35:55Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T19:05:11.205633Z"}],"nvd":[{"id":"CVE-2026-42346","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.","status":"published","published":"2026-05-08T23:16:37.903Z","modified":"2026-07-24T21:10:00.143Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:12:18.239974Z"}],"osv":[{"id":"CVE-2026-42346","title":"Postiz: TOCTOU DNS rebinding bypasses all SSRF URL validation paths","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.","status":"published","published":"2026-05-08T22:26:50.501Z","modified":"2026-10-28T02:30:33.128479696Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N","level":"medium"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:45:04.117819Z"}]}}