AUGUST 16, 2026
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Case File

CVE-2026-45809

HIGH · CVSS 8.7 EPSS 0.39% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-05 · Last synced 2026-08-16

CyberRota Analysis

AI-Generated

OpenSIPS versions prior to 3.6.6 and 4.0.0-rc1 are vulnerable to a denial of service attack due to a buffer overflow in the watcherinfo generation process, which can be exploited by sending a specially crafted SUBSCRIBE Event: presence request. This vulnerability can lead to the crashing of OpenSIPS worker processes, impacting systems that expose the handle_subscribe() function and allow watcherinfo generation. Organizations using affected versions should prioritize upgrading to the patched versions to mitigate potential disruptions in service.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-45809
Severity
HIGH
CVSS
8.7
EPSS
0.39%

Original NVD Description

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.