CVE-2026-19264: Unauthenticated arbitrary file read via /uploads path traversal (URL-encoded separators) leading to instance takeover

Vulnerability summary

CVE-2026-19264 is a critical (CVSS 9.8) Path Traversal vulnerability in gitroomhq postiz-app. EPSS estimates a 1.01% chance of exploitation in the next 30 days, higher than 62.9% of scored vulnerabilities.

Timeline

1. 07-08-2026
   PublishedVulnerability first disclosed.
2. 24-08-2026
   Last modifiedVulnerability information updated.

Description

Postiz is an open-source social media scheduling tool. The route that serves locally stored media joins URL-supplied path segments onto the upload directory and streams the file without normalising the path or confining it to that directory, and the route requires no authentication. Raw dot-segments are collapsed before routing, but URL-encoded separators survive route matching and are decoded only once they reach the handler, restoring the traversal at the filesystem call. An unauthenticated remote attacker can therefore read any file readable by the application process, including the process environment, which exposes the JWT signing secret, the database connection string, and connected provider and billing secrets. Because session tokens are signed with that secret and carry no expiry, this allows forging a non-expiring session as any user, including an administrator, without a password.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.