CVE-2026-45084: OpenSIPS presence module denial of service in handle_publish

CVE-2026-45084 · Severity: info · CVSS 7.5 · Published 2026-08-04

OpenSIPS is a Session Initiation Protocol (SIP) server used by telecommunications and VoIP service providers to route and manage voice calls. The presence module handles notifications about user availability status. A vulnerability in this module allows a remote attacker to crash an OpenSIPS instance by sending a specially crafted SIP PUBLISH request, causing service outage and disrupting call routing and presence notifications for all users on the affected server.

Technologies: OpenSIPS. Vendors: OpenSIPS.

Quick answers

Is CVE-2026-45084 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-45084 being exploited in the wild.
How severe is CVE-2026-45084?
Informational severity, with a CVSS score of 7.5, published 4 August 2026.
Which products and versions are affected?
OpenSIPS 3.4.0 through 3.6.5, 4.0.0 through 4.0.0.
Is there a fix for CVE-2026-45084?
A patch was published on 2026-05-21: Fixed in OpenSIPS 3.6.6 and 4.0.0-rc1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-45084 attacked?
It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-45084?
Check whether you run OpenSIPS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a NULL pointer dereference in the presence module's handle_publish() function. When processing a SIP PUBLISH request with Event: presence header and enable_sphere_check=1 configuration enabled, the code calls get_content_type() macro without first calling parse_content_type_hdr(). This causes a crash when msg->content_type->parsed is NULL (if Content-Type header is present but unparsed) or when msg->content_type is NULL (if Content-Type header is missing entirely). The attack requires only a single PUBLISH request over UDP or TCP and does not require authentication at the protocol level, though deployment routing configurations may enforce it. The vulnerability was fixed in OpenSIPS 3.6.6 and 4.0.0-rc1.

Affected products

  • OpenSIPS OpenSIPS 3.4.0 through 3.6.5, 4.0.0 through 4.0.0

Timeline

  • 2026-05-21: disclosed: GitHub security advisory GHSA-h3ww-hchh-x2g9 published
  • 2026-05-21: patched: Fixed in OpenSIPS 3.6.6 and 4.0.0-rc1
  • 2026-08-04: other: CVE-2026-45084 published

References

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