CVE-2026-116748: transmission · Permissive Cross-domain Security Policy with Untrusted Domains
Affects transmissionSource CVE Database V5
Not known to be exploited · CVSS 8.7 High : upgrade to 4.1.3 soon.
Data as of 26 Oct 2026, 22:15 UTC
- Patch
- Available – fixed in 4.1.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade transmission to 4.1.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| transmissiontransmission | Affected
| Fixed in
|
GitHubtransmissionpkg:github/transmissionOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Transmission to version 4.1.3 or later, where this vulnerability is fixed. No additional mitigation is necessary once the update is applied.
Description
Transmission versions 4.0.0 through 4.1.2 have a permissive Cross-Origin Resource Sharing (CORS) vulnerability in the handle_request() function of rpc-server.cc. This flaw exposes the X-Transmission-Session-Id anti-CSRF token to any web origin, allowing malicious web pages to read and reuse the token to perform unauthorized RPC calls. Exploitation can lead to script-torrent-done execution, changes to the download directory, or deletion of torrents and data. The vulnerability is fixed in version 4.1.3.
References
- github.com/transmission/transmission/pull/8938 (opens in a new tab)
- github.com/transmission/transmission/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e (opens in a new tab)
- github.com/transmission/transmission (opens in a new tab)
- github.com/transmission/transmission/releases/tag/4.1.3 (opens in a new tab)
- github.com/transmission/transmission/blob/4.1.2/libtransmission/rpc-server.cc (opens in a new tab)
- joshua.hu/transmission-cors-rpc-csrf-rce-drive-by-exploit (opens in a new tab)
- vulncheck.com/advisories/transmission-4.0.0-before-4.1.3-permissive-cors-leaks-rpc-anti-csrf-token (opens in a new tab)