9

CVE-2026-40487

Exploit

Postiz Has Unrestricted File Upload via MIME Type Spoofing that Leads to Stored XSS

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Gitroom ≫ Postiz Version < 2.21.6
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.22% 0.128
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 9 2.3 6
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
security-advisories@github.com 8.9 2.3 6
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L
CWE-345 Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

CWE-434 Unrestricted Upload of File with Dangerous Type

The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx
Vendor Advisory
Exploit
https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6
Product
Release Notes