Kamailio: >> Kamailio >> 5.5.0 Security Vulnerabilities
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.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-08
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.
CVSS Score
4.4
EPSS Score
0.002
Published
2026-04-08
A security vulnerability has been detected in Kamailio 5.5. Impacted is the function rve_destroy of the file src/core/rvalue.c of the component Configuration File Handler. The manipulation leads to heap-based buffer overflow. The attack must be carried out locally. The exploit has been disclosed publicly and may be used. There is ongoing doubt regarding the real existence of this vulnerability. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way.
CVSS Score
4.8
EPSS Score
0.0
Published
2025-10-27
A vulnerability was detected in Kamailio 5.5. The affected element is the function sr_push_yy_state of the file src/core/cfg.lex of the component Configuration File Handler. The manipulation results in use after free. The attack must be initiated from a local position. The exploit is now public and may be used. The real existence of this vulnerability is still doubted at the moment. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way.
CVSS Score
4.8
EPSS Score
0.0
Published
2025-10-27
A flaw has been found in Kamailio 5.5. The impacted element is the function rve_is_constant of the file src/core/rvalue.c. This manipulation causes null pointer dereference. The attack needs to be launched locally. The exploit has been published and may be used. It is still unclear if this vulnerability genuinely exists. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way.
CVSS Score
4.8
EPSS Score
0.0
Published
2025-10-27
A vulnerability has been found in Kamailio 5.5. This affects the function yyerror_at of the file src/core/cfg.y of the component Grammar Rule Handler. Such manipulation leads to null pointer dereference. The attack needs to be performed locally. The exploit has been disclosed to the public and may be used. The actual existence of this vulnerability is currently in question. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way.
CVSS Score
4.8
EPSS Score
0.0
Published
2025-10-27