CVE-2026-45809

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 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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/OpenSIPS/opensips/commit/c5970d3ee25b457ad2d78fe6e9662a12dae577cd
https://github.com/OpenSIPS/opensips/commit/dd86461b71ff4a4f5194205896ae5f48f144240d
https://github.com/OpenSIPS/opensips/security/advisories/GHSA-gx83-2gh8-7v56
https://github.com/OpenSIPS/opensips/security/advisories/GHSA-gx83-2gh8-7v56

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-05 00:17

Updated : 2026-09-08 20:41

NVD link : CVE-2026-45809

Mitre link : CVE-2026-45809

CVE.ORG link : CVE-2026-45809

JSON object : View

Products Affected

No product.

CWE

CWE-121

Stack-based Buffer Overflow

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