CVE-2026-39863
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk38th percentile - higher than 38% of all known CVEs
Summary
In Kamailio (formerly OpenSER and SER) prior to versions 6.1.1, 6.0.6, and 5.8.8, an out-of-bounds access vulnerability exists in the core. A remote attacker can send a specially crafted TCP packet, causing a process crash (denial of service). This affects Kamailio instances with TCP or TLS listeners.
Risk Assessment
An attacker can remotely crash the SIP server, causing disruption to VoIP communications and other services relying on Kamailio.
Recommendation
Upgrade Kamailio to version 6.1.1, 6.0.6, or 5.8.8 depending on the branch in use.
Other vulnerabilities in Kamailio
See all- CVE-2015-1590High
The kamcmd administrative utility and default configuration in kamailio before version 4.3.0 use the /tmp/kamailio_ctl directory.
- CVE-2015-1591High
Versions of kamailio before 4.2.0-2 have a vulnerability that allows local users to gain elevated privileges.
- CVE-2013-7426Critical
CVE-2013-7426 identifies an insecure handling of temporary files in kamailio 4.0.1, specifically concerning the /tmp/kamailio_fifo file. This may lead to unauthorized access to data.
- CVE-2026-39864Medium
Kamailio before versions 6.0.5 and 5.8.7 contains an out-of-bounds read vulnerability in the auth module. A specially crafted SIP packet can cause a process crash (DoS) after successful user authentication without a database backend.
Original NVD description (English source)
Kamailio is an open source implementation of a SIP Signaling Server. Prior to 6.1.1, 6.0.6, and 5.8.8, an out-of-bounds access in the core of Kamailio (formerly OpenSER and SER) allows remote attackers to cause a denial of service (process crash) via a specially crafted data packet sent over TCP. The issue impacts Kamailio instances having TCP or TLS listeners. This vulnerability is fixed in 5.1.1, 6.0.6, and 5.8.8.