CVE-2026-116748
Transmission 4.0.0 before 4.1.3 Permissive CORS Leaks RPC Anti-CSRF Token
CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-942 |
| Vendor | transmission |
| Product | transmission |
| Published | Oct 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
transmission / transmission
4.0.0 < 4.1.3
References
github.com: https://github.com/transmission/transmission/pull/8938 github.com: https://github.com/transmission/transmission/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e github.com: https://github.com/transmission/transmission github.com: https://github.com/transmission/transmission/releases/tag/4.1.3 github.com: https://github.com/transmission/transmission/blob/4.1.2/libtransmission/rpc-server.cc#L560 joshua.hu: https://joshua.hu/transmission-cors-rpc-csrf-rce-drive-by-exploit vulncheck.com: https://www.vulncheck.com/advisories/transmission-4.0.0-before-4.1.3-permissive-cors-leaks-rpc-anti-csrf-token
Credits
Joshua Rogers ckerr