NVD security advisory
Security advisory for Transmission 4.0.0
CVE-2026-116748
Full advisory details, affected packages, severity context, and original source.
Affected technology
Transmission 4.0.0Affected product
Advisory overview
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.
Related 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