{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40487","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-04-13T19:50:42.114Z","datePublished":"2026-04-18T01:19:06.588Z","dateUpdated":"2026-04-20T15:25:40.893Z"},"containers":{"cna":{"title":"Postiz Has Unrestricted File Upload via MIME Type Spoofing that Leads to Stored XSS","problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-434","lang":"en","description":"CWE-434: Unrestricted Upload of File with Dangerous Type","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":8.9,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L","version":"3.1"}}],"references":[{"name":"https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx","tags":["x_refsource_CONFIRM"],"url":"https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx"},{"name":"https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6","tags":["x_refsource_MISC"],"url":"https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6"}],"affected":[{"vendor":"gitroomhq","product":"postiz-app","versions":[{"version":"< 2.21.6","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-04-18T01:19:06.588Z"},"descriptions":[{"lang":"en","value":"Postiz is an AI social media scheduling tool. Prior to version 2.21.6, a file upload validation bypass allows any authenticated user to upload arbitrary HTML, SVG, or other executable file types to the server by spoofing the `Content-Type` header. The uploaded files are then served by nginx with a Content-Type derived from their original extension (`text/html`, `image/svg+xml`), enabling Stored Cross-Site Scripting (XSS) in the context of the application's origin. This can lead to session riding, account takeover, and full compromise of other users' accounts. Version 2.21.6 contains a fix."}],"source":{"advisory":"GHSA-44wg-r34q-hvfx","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-20T15:25:37.579242Z","id":"CVE-2026-40487","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-04-20T15:25:40.893Z"}}]}}