CVE-2026-49338 is a high-severity security vulnerability in go.senan.xyz/gonic (go), affecting versions <= 0.20.1. It is fixed in 0.21.0.
Summary In gonic, the Subsonic API endpoints /rest/deletePlaylist.view and /rest/getPlaylist.view perform no per-resource authorization. Once authenticated as any user (admin or not), an attacker can: Delete any playlist owned by any other user (including admin) by passing its id. Read the full contents (name, comment, song list) of any other user's private (non-public) playlist by passing its id. The Subsonic playlist id is base64url("<userID>/<filename>.m3u"). Because filenames are user-supplied or time-derived and the userID is a small integer, IDs are guessable and frequently exposed (e.g. a previously-public playlist that was later made private still has the same ID). This breaks the multi-user trust boundary of gonic: a low-privileged user can wipe an administrator's curated playlists, and a user can exfiltrate any private playlist they obtain an ID for. Status This was originally disclosed to the maintainer by email and has been fixed in commit 6dd71e6a3c966867ef8c900d359a7df75789f410 (fix(subsonic): enforce playlist ownership on getPlaylist/deletePlaylist, 2026-05-18). The fix has not yet been included in a tagged release; the latest tagged version v0.20.1 is still vulnerable. Filing this advisory now that private vulnerability reporting is enabled on the repo, so the issue has a public record once the next release ships. Vulnerable code (pre-fix, at v0.20.1 / commit 37090aa7) Delete IDOR, server/ctrlsubsonic/handlersplaylist.go lines 177-187: The handler never loads the playlist to check playlist.UserID == user.ID. Compare to ServeUpdatePlaylist (same file, line 138) which does perform this check. Read IDOR, server/ctrlsubsonic/handlersplaylist.go lines 51-68: The listing endpoint ServeGetPlaylists (line 38) correctly filters by playlist.UserID != user.ID && !playlist.IsPublic, but the singular getPlaylist did not. Live PoC (passing Go test) A reproducer against the existing test fixture (server/ctrlsubsonic): Test output: Equivalent HTTP request Response: {"subsonic-response":{"status":"ok","version":"..."}}, playlist is gone. Impact Integrity / Availability: low-privileged users can delete any other user's playlists, including admin's curated lists. There is no undo. Confidentiality: private playlists (including their comment fields) are readable by any authenticated user with an ID. IDs are predictable (base64("<smallUserID>/<name>.m3u")) and previously-public IDs persist after being marked private. Trust boundary: gonic supports multiple users (createUser, non-admin role). This bug collapsed the user-to-user authorization model. Affected versions Latest tagged release v0.20.1 and all prior versions back to when the playlist M3U store was introduced. Master HEAD is fixed at commit 6dd71e6a3c966867ef8c900d359a7df75789f410. Suggested patch (applied by maintainer in 6dd71e6) Load the playlist first and enforce ownership in both handlers: This mirrors the existing ownership check already present in ServeCreateOrUpdatePlaylist (line 84) and ServeUpdatePlaylist (line 138). Credits Reported by Vishal Shukla (@shukla304 / @therawdev).
CVE-2026-49338 has a CVSS score of 7.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (0.21.0). Upgrading removes the vulnerable code path.
go
go.senan.xyz/gonic (<= 0.20.1)go.senan.xyz/gonic → 0.21.0 (go)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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CVE-2026-49338 is a high-severity security vulnerability in go.senan.xyz/gonic (go), affecting versions <= 0.20.1. It is fixed in 0.21.0.
CVE-2026-49338 has a CVSS score of 7.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
go.senan.xyz/gonic (go) versions <= 0.20.1 is affected.
Yes. CVE-2026-49338 is fixed in 0.21.0. Upgrade to this version or later.
Whether CVE-2026-49338 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade go.senan.xyz/gonic to 0.21.0 or later.