Buffer overflow in Kamailio

CVE-2025-12205

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.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (11.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

Affected products

  • Kamailio — versions 5.5.0
  • N/a Kamailio — versions 5.5

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-12205?
CVE-2025-12205 is a medium-severity vulnerability in Kamailio, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2025-10-27.
How severe is CVE-2025-12205?
Medium severity. CVSS v3 base score is 5.3 out of 10.