CVE-2026-116748

EUVD-2026-110496
Transmission 4.0.0 before 4.1.3 contains a permissive CORS vulnerability in handle_request() in rpc-server.cc that exposes the X-Transmission-Session-Id anti-CSRF token to any web origin. Malicious web pages can read the token from the 409 handshake response and replay it to issue RPC calls, enabling script-torrent-done execution, download-dir changes, or torrent and data deletion.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
8.8 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 44.46%
Debian logo
Debian Releases
Debian Product
Codename
transmission
bookworm
vulnerable
forky
4.1.3+dfsg-1
fixed
sid
4.1.3+dfsg-1
fixed
trixie
vulnerable
Common Weakness Enumeration
References
https://github.com/transmission/transmission
https://github.com/transmission/transmission/blob/4.1.2/libtransmission/rpc-server.cc#L560
https://github.com/transmission/transmission/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e
https://github.com/transmission/transmission/pull/8938
https://github.com/transmission/transmission/releases/tag/4.1.3
https://joshua.hu/transmission-cors-rpc-csrf-rce-drive-by-exploit
https://www.vulncheck.com/advisories/transmission-4.0.0-before-4.1.3-permissive-cors-leaks-rpc-anti-csrf-token