CVE-2026-111728: Seanime v3.10.3 Argument Injection via TranscodeHwAccelCustomSettings

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-16 · updated 2026-10-16
Weakness: CWE-88

Description

Seanime v3.7.0 to v3.10.3 contains an argument injection vulnerability reachable through improper authorization, allowing unauthenticated LAN or Tailnet clients to bypass the privileged mediastream settings guard by setting transcodeHwAccel to custom and supplying attacker-controlled decodeFlags and encodeFlags via the transcodeHwAccelCustomSettings field, which are appended verbatim to the ffmpeg argument vector. Attackers can trigger execution via the mediastream request and HLS playlist endpoints to achieve arbitrary file write and file truncation on the host as the user running seanime, with the injected input options also enabling potential arbitrary local file read and outbound data exfiltration through ffmpeg's protocol handlers.

Affected products

5rahim Seanime: from 3.7.0 before 3.10.4 — fixed in 3.10.4

How to fix

Upgrade to a fixed version: 5rahim Seanime 3.10.4. Check the vendor advisory for mitigations.

References

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