{"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": "2026-04-18T01:19:06.588Z"}, "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"}}}}

{}

{"cveTags": [], "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."}], "id": "CVE-2026-40487", "lastModified": "2026-04-18T02:16:11.670", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 2.3, "impactScore": 6.0, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-04-18T02:16:11.670", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6"}, {"source": "security-advisories@github.com", "url": "https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}, {"lang": "en", "value": "CWE-345"}, {"lang": "en", "value": "CWE-434"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}