CVE-2026-73291

Seerr: Path traversal to RCE via /avatarproxy image cache filename from upstream ETag

Published Aug 12, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Seerr-team
Seerr-team seerr
Vendors & Products Seerr-team
Seerr-team seerr
Type Values Removed Values Added
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.
Title Seerr: Path traversal to RCE via /avatarproxy image cache filename from upstream ETag
Weaknesses CWE-22
CWE-94
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 13, 2026, 4:23 PM
Reserved
Aug 11, 2026, 7:42 PM
Status
Deferred
Published
Aug 12, 2026, 3:18 PM
Modified
Oct 24, 2026, 3:10 PM