# CVE-2026-39864: kamailio: Kamailio is an open source implementation of a SIP Signaling Server

CVE-2026-39864 is fixed in kamailio on 1 platform, first by DEBIAN-CVE-2026-39864, released April 8, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-39864
- Priority: Routine
- CVSS: 4.9 (medium)
- EPSS: 0.0031
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 8, 2026

## Description

Kamailio is an open source implementation of a SIP Signaling Server. Prior to 6.0.5 and 5.8.7, an out-of-bounds read in the auth module of Kamailio (formerly OpenSER and SER) allows remote attackers to cause a denial of service (process crash) via a specially crafted SIP packet if a successful user authentication without a database backend is followed by additional user identity checks. This vulnerability is fixed in 6.0.5 and 5.8.7.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kamailio Debian 13.5 (trixie) | 6.0.1-1+deb13u2 | [DEBIAN-CVE-2026-39864](https://patchblox.com/security/data/fix/linux/debian-cve-2026-39864.md) | Apr 8, 2026 |
| Linux | kamailio Debian 14 | 6.0.5-1 | [DEBIAN-CVE-2026-39864](https://patchblox.com/security/data/fix/linux/debian-cve-2026-39864.md) | Apr 8, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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