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.
References3
Metrics
- CVSS 3.1
-
5.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - CVSS 4.0
-
5.3
MEDIUM
Score source: CNA
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 17 · as of 10 November 2026
- CWE
- CWE-88
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.