CVE-2026-73291
HIGH
MEDIUM
Priority: 0.03
BB Relevance:
49/100
Published: 2026-08-12
Modified: 2026-10-24
First seen: 2026-10-29
Status: active
Attack Surface
Adjacent
No Auth
No Interaction
Integ. Impact
CVSS Vector Breakdown
AV:
Adjacent
AC:
High
PR:
None
UI:
None
S:
Unchanged
C:
Low
I:
High
A:
High
Description
Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Prior to version 3.4.0, Seerr's ImageProxy in server/lib/imageproxy.ts uses the upstream ETag and Content-Type response headers to build a cache filename for the unauthenticated GET /avatarproxy/:jellyfinUserId route, allowing a malicious or compromised Jellyfin or Emby server, or a man-in-the-middle attacker on a plaintext media-server connection, to supply traversal sequences that path.join and fs.writeFile normalize outside the cache directory, overwrite /app/dist/index.js or other files, and execute code as the node user after a container restart. This issue is fixed in version 3.4.0.