Transmission 4.0.0 before 4.1.3 contains a permissive CORS vulnerability in handle_request() in rpc-server.cc that exposes the X-Transmis…
CVE-2026-116748 · GHSA-jw4h-7968-5hj9 · EUVD-2026-110496 · published 26 Oct 2026
How serious is it
- Severity: high, CVSS score 8.7 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-116748?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- transmission transmission: 4.0.0 <4.1.3
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
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.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- github.com/transmission/transmission/pull/8938
- github.com/transmission/transmission/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e
- github.com/transmission/transmission
- github.com/transmission/transmission/releases/tag/4.1.3
- github.com/transmission/transmission/blob/4.1.2/libtransmission/rpc-server.cc#L560
- joshua.hu/transmission-cors-rpc-csrf-rce-drive-by-exploit
- www.vulncheck.com/advisories/transmission-4.0.0-before-4.1.3-permissive-cors-leaks-rpc-anti-csrf-token
Merged from ENISA EUVD. Last updated 27 Oct 2026. All vulnerabilities · RSS · JSON