gonic: Path Traversal in playlist id bypasses ownership check, enabling any user to read/delete other users' playlists

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.1 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

EPSS

• CVE-2026-49339: 0.31% estimated exploitation activity in the next 30 days; percentile 24.27 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The maintainer's recent fix in 6dd71e6a3c966867ef8c900d359a7df75789f410 (fix(subsonic): enforce playlist ownership on getPlaylist/deletePlaylist) added an ownership check based on playlist.UserID. However, playlist.UserID is derived from the first path segment of the attacker-controlled playlist ID, with no path containment on the resolved file path. Any authenticated Subsonic user can therefore bypass the ownership check and: 1. Read any other user's playlist (name, comment, IsPublic flag, song list) by crafting a base64-encoded playlist ID whose first segment matches their own user ID, followed by .. traversal segments pointing into another user's playlist directory. 2. Delete any other user's playlist (including admin's curated playlists) by the same trick against deletePlaylist. 3. Probe arbitrary file paths on the host for existence/readability. This is a bypass of the boundary the 6dd71e6 fix is trying to enforce; it is closely related to the original GONIC-1 IDOR but…

Published by the source

26 Jun 2026, 23:32 UTC

Last modified by the source

26 Jun 2026, 23:32 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2fp4-5v5c-4448

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# Patch Next advisory brief: CVE-2026-49339

Advisory: gonic: Path Traversal in playlist `id` bypasses ownership check, enabling any user to read/delete other users' playlists
IDs: CVE-2026-49339, GHSA-2fp4-5v5c-4448
Record: https://patchnext.com/advisories/cve-2026-49339 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: go.senan.xyz/gonic 0.21.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go go.senan.xyz/gonic: affected <= 0.20.1; fixed in 0.21.0

## Suggested inspection (read-only)
- Go go.senan.xyz/gonic: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on go.senan.xyz/gonic.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2fp4-5v5c-4448 (GitHub-reviewed advisory GHSA-2fp4-5v5c-4448 lists affected ranges: Go go.senan.xyz/gonic >=0 <=0.20.1)

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