CVE-2026-49339: gonic is a music streaming server / free-software subsonic server API implementation.

gonic is a music streaming server / free-software subsonic server API implementation.

gonic is a music streaming server / free-software subsonic server API implementation. The maintainer's fix in commit `6dd71e6a3c966867ef8c900d359a7df75789f410` 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 read any other user's playlist, delete any other user's playlist, and 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 uses a different primitive (path traversal in the `id` parameter rather than direct cross-user access). Commit 0824bed88f6bbc490ba28bf09d28e5dfeb07b445 in version 0.21.0 fixes the issue.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses gonic, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.31%, higher than 24% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

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Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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