CVE-2026-39863

Name: CVE-2026-39863
Creator: NVD / NIST
Published: 2026-04-08T20:16:26.55+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.46%

Last modified Jun 17, 2026

CVE-2026-39863 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.46% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.46%

36.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-119

Affected Software

Vendor	Product	Versions
Kamailio	Kamailio	< 5.8.8
Kamailio	Kamailio	>= 6.0.0, < 6.0.6
Kamailio	Kamailio	6.1.0

References

https://github.com/kamailio/kamailio/security/advisories/GHSA-2wj4-f825-2h2fVendor Advisory

Timeline

Published: Apr 8, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-39863?

How severe is CVE-2026-39863?

CVE-2026-39863 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.46% probability of exploitation in the next 30 days.

How do I fix CVE-2026-39863?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-39863?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST