High 8.8Published Oct 26, 2026

CVE-2026-116748Transmission 4.0.0 before 4.1.3 Permissive CORS Leaks RPC Anti-CSRF Token

Updated under an hour ago (Oct 28, 2026, 1:00 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-942
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Awaiting Analysis
Record last updated: Oct 26, 2026
First seen by InfoSec Signals: Oct 26, 2026

Affected products

Affected products

transmission transmission transmission:transmission (from the name)	from 4.0.0 before 4.1.3	CNA record

References

References

https://github.com/transmission/transmission/pull/8938	issue-tracking, patch
https://github.com/transmission/transmission/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e	patch
https://github.com/transmission/transmission	product
https://github.com/transmission/transmission/releases/tag/4.1.3	release-notes
https://github.com/transmission/transmission/blob/4.1.2/libtransmission/rpc-server.cc#L560	technical-description
https://joshua.hu/transmission-cors-rpc-csrf-rce-drive-by-exploit	third-party-advisory
https://www.vulncheck.com/advisories/transmission-4.0.0-before-4.1.3-permissive-cors-leaks-rpc-anti-csrf-token	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.