CVE-2026-39864: Kamailio

Medium severity, CVSS 4.9. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Kamailio Kamailio: before 5.8.7 (fixed in 5.8.7); from 6.0.0, before 6.0.5 (fixed in 6.0.5)

Published 2026-04-08. Last modified 2026-07-24.