{"id":"CVE-2026-45809","title":"OpenSIPS is a Session Initiation Protocol (SIP) server implementation","summary":"OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions prior to 3.6.6 and 4.0.0-rc1 contain a denial of service vulnerability in the watcherinfo generation functionality. An attacker can create an oversized watch…","severity":"none","cwe":["CWE-121"],"published":"2026-08-05","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:41:31.497","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-45809","references":[{"url":"https://github.com/OpenSIPS/opensips/commit/c5970d3ee25b457ad2d78fe6e9662a12dae577cd","label":"security-advisories@github.com"},{"url":"https://github.com/OpenSIPS/opensips/commit/dd86461b71ff4a4f5194205896ae5f48f144240d","label":"security-advisories@github.com"},{"url":"https://github.com/OpenSIPS/opensips/security/advisories/GHSA-gx83-2gh8-7v56","label":"security-advisories@github.com"},{"url":"https://github.com/OpenSIPS/opensips/security/advisories/GHSA-gx83-2gh8-7v56","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd"],"epss":0.00388,"epssPercentile":0.32666,"ingestedAt":"2026-09-08T21:11:12.267Z","slug":"CVE-2026-45809","body":"## Overview\n\nOpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions prior to 3.6.6 and 4.0.0-rc1 contain a denial of service vulnerability in the watcherinfo generation functionality. An attacker can create an oversized watcher entry by sending a SUBSCRIBE Event: presence request with a long From URI, and then trigger presence.winfo watcherinfo XML generation for the same presentity. OpenSIPS copies the stored watcher URI into a fixed-size stack buffer, overflowing it and crashing the process. A remote attacker can crash an OpenSIPS worker in deployments that expose handle_subscribe() and allow watcherinfo (presence.winfo) generation. The issue is configuration-dependent because the presence and presence_xml modules must be loaded and SUBSCRIBE routing must be reachable. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}