CVE-2026-116748

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

8.7 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Passive

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

1.25%Up 0.7 points since Oct 27, 2026

What each source reports

CVE List Score used 8.7

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

Record: CVE-2026-116748
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness: CWE-942
Updated: 2026-11-02

EUVDEUVD-2026-110496 8.7

Record: EUVD-2026-110496
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-jw4h-7968-5hj9 8.7

Transmission 4.0.0 before 4.1.3 contains a permissive CORS vulnerability in handle_request() in...

Record: GHSA-jw4h-7968-5hj9
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness: CWE-942
Updated: 2026-11-02

NVD 8.7

Record: CVE-2026-116748
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness: CWE-942
Updated: 2026-11-02

OSV 8.7

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

Record: CVE-2026-116748
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-942
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-116748 8.7

Record: DEBIAN-CVE-2026-116748
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-116748 8.7

Record: UBUNTU-CVE-2026-116748
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Updated: 2026-11-02

Affected products

transmission

Affected packages

Affected packages
Package	Affected	Fixed
`transmission` Debian:12	All versions, plus listed versions 3.00-2.13.00-2.1+deb12u14.0.1-14.0.2-14.0.5-1 Show 23 moreShow less 4.0.5-24.0.5-34.0.6+dfsg-14.0.6+dfsg-24.0.6+dfsg-34.1.0+dfsg-14.1.0+dfsg-1~bpo13+14.1.0~beta1+dfsg-14.1.0~beta2+dfsg-14.1.0~beta2+dfsg-24.1.0~beta2+dfsg-34.1.0~beta2+dfsg-44.1.0~beta2+dfsg-54.1.0~beta3+dfsg-14.1.0~beta4+dfsg-14.1.0~beta5+dfsg-14.1.1+dfsg-14.1.1+dfsg-1~bpo13+14.1.2+dfsg-14.1.2+dfsg-1~bpo13+14.1.3+dfsg-14.1.3+dfsg-1~bpo13+14.1.4+dfsg-1	None known
`transmission` Debian:13	All versions, plus listed versions 4.1.0+dfsg-14.1.0+dfsg-1~bpo13+14.1.0~beta2+dfsg-34.1.0~beta2+dfsg-3+deb13u14.1.0~beta2+dfsg-3+deb13u2 Show 12 moreShow less 4.1.0~beta2+dfsg-44.1.0~beta2+dfsg-54.1.0~beta3+dfsg-14.1.0~beta4+dfsg-14.1.0~beta5+dfsg-14.1.1+dfsg-14.1.1+dfsg-1~bpo13+14.1.2+dfsg-14.1.2+dfsg-1~bpo13+14.1.3+dfsg-14.1.3+dfsg-1~bpo13+14.1.4+dfsg-1	None known
`transmission` Debian:14	before 4.1.3+dfsg-1, plus listed versions 4.1.0+dfsg-14.1.0+dfsg-1~bpo13+14.1.0~beta2+dfsg-34.1.0~beta2+dfsg-44.1.0~beta2+dfsg-5 Show 8 moreShow less 4.1.0~beta3+dfsg-14.1.0~beta4+dfsg-14.1.0~beta5+dfsg-14.1.1+dfsg-14.1.1+dfsg-1~bpo13+14.1.2+dfsg-14.1.2+dfsg-1~bpo13+14.1.3+dfsg-1~bpo13+1	4.1.3+dfsg-1
`transmission` Ubuntu:16.04:LTS	All versions, plus listed versions 2.84-1ubuntu12.84-22.84-32.84-3ubuntu12.84-3ubuntu22.84-3ubuntu32.84-3ubuntu3.1	None known
`transmission` Ubuntu:18.04:LTS	All versions, plus listed versions 2.92-2ubuntu32.92-3ubuntu12.92-3ubuntu2	None known
`transmission` Ubuntu:20.04:LTS	All versions, plus listed versions 2.94-2ubuntu12.94-2ubuntu22.94-2ubuntu3	None known
`transmission` Ubuntu:22.04:LTS	All versions, plus listed versions 3.00-1ubuntu23.00-1ubuntu53.00-2ubuntu13.00-2ubuntu23.00-2ubuntu2.13.00-2ubuntu2.2	None known
`transmission` Ubuntu:24.04:LTS	All versions, plus listed versions 4.0.2-1ubuntu34.0.5-14.0.5-1build34.0.5-1build44.0.5-1build54.0.5-1ubuntu0.1	None known
`transmission` Ubuntu:26.10	All versions, plus listed versions 4.1.1+dfsg-1ubuntu14.1.2+dfsg-1ubuntu14.1.3+dfsg-1ubuntu14.1.3+dfsg-1ubuntu2	None known
`transmission` Ubuntu:26.04:LTS	All versions, plus listed versions 4.1.0~beta2+dfsg-3ubuntu14.1.0~beta2+dfsg-3ubuntu24.1.0~beta4+dfsg-1ubuntu14.1.0~beta5+dfsg-1ubuntu14.1.0+dfsg-1ubuntu14.1.1+dfsg-1ubuntu14.1.1+dfsg-1ubuntu1.1	None known

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
Nuclei	Transmission 4.0.0-4.1.2 - Permissive CORS Exposes RPC Session ID

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, Nuclei, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-116748 is a high vulnerability (CVSS 8.7) in Transmission, published October 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.25%, the 69th percentile. Fixed in transmission 4.1.3+dfsg-1.

References

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