CVE-2026-49339
HIGHgonic is a music streaming server / free-software subsonic server API implementation. The maintainer's fix in commit `6dd71e6a3c966867ef8c900d359a7df75789f410` added an ownership check…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-49339 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-49339 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-49339. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-49339 in your dependencies?
O3 detects CVE-2026-49339 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.