--- title: "CVE-2026-116748: Transmission - Broken Access Control" description: "Transmission < 4.1.3 contains a CORS misconfiguration caused by permissive CORS in handle_request() in rpc-server.cc, letting remote attackers steal X-Transmission-Session-Id token and perform unauthorized RPC calls, exploit requires attacker to host malicious web pages." url: https://panop.io/threat-heartbeat/CVE-2026-116748/ --- # CVE-2026-116748 Transmission - Broken Access Control Transmission < 4.1.3 contains a CORS misconfiguration caused by permissive CORS in handle\_request() in rpc-server.cc, letting remote attackers steal X-Transmission-Session-Id token and perform unauthorized RPC calls, exploit requires attacker to host malicious web pages. CVSS base score 8.8 /10 High CISA KEV Not listed Public exploit None known Authentication Not required [View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-116748) ## Details Type Broken Access Control Impact Broken Access Control CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Published 26 October 2026 Updated 27 October 2026 Weakness [CWE-942](https://cwe.mitre.org/data/definitions/942.html) ## Vendor fix Update to version 4.1.3 or later. Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them. ## References - [https://nvd.nist.gov/vuln/detail/CVE-2026-116748](https://nvd.nist.gov/vuln/detail/CVE-2026-116748) - [https://github.com/transmission/transmission/releases/tag/4.1.3](https://github.com/transmission/transmission/releases/tag/4.1.3) - [https://joshua.hu/transmission-cors-rpc-csrf-rce-drive-by-exploit](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](https://www.vulncheck.com/advisories/transmission-4.0.0-before-4.1.3-permissive-cors-leaks-rpc-anti-csrf-token) - [https://github.com/transmission/transmission](https://github.com/transmission/transmission) - [https://github.com/transmission/transmission/blob/4.1.2/libtransmission/rpc-server.cc#L560](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/commit/c6a1bd2017a0fea9c956737c213f23e4b0f7929e) - [https://github.com/transmission/transmission/pull/8938](https://github.com/transmission/transmission/pull/8938) [← All CVEs](https://panop.io/threat-heartbeat/) ## What this record can't tell you - Whether you run the affected software, and where - Whether an attacker can actually reach and exploit it - The misconfigurations that never get a CVE number - What it would cost the business, ranked into what to fix first Panop answers these inside your environment, for this CVE and every other finding. [Book a demo](https://panop.io/demo)