CVE-2026-116748
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 1.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.2% in the next 30 days (EPSS).
- Severity: 8.7 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.2% · EPSS, next 30 days
- Weakness
- CWE-942
- Record status
- Awaiting Analysis
Attack profile CVSS 4.0 · 8.7
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- None
- User interaction
- Passive
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS: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
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-116748.md and follow it. Check whether this project is affected by CVE-2026-116748. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/transmission/transmission/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e
- https://github.com/transmission/transmission/pull/8938
- https://github.com/transmission/transmission/releases/tag/4.1.3
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