Kamailio up to 5.8.6/6.0.4 Auth out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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3.2$0-$5k0.30

Summaryinfo

A vulnerability classified as problematic has been found in Kamailio up to 5.8.6/6.0.4. Impacted is an unknown function of the component Auth Module. This manipulation causes out-of-bounds. This vulnerability appears as CVE-2026-39864. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Kamailio up to 5.8.6/6.0.4. Affected by this vulnerability is some unknown processing of the component Auth Module. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-39864 since 04/07/2026. The exploitation appears to be difficult. The attack can be launched remotely. Additional levels of successful authentication are necessary for exploitation. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 305789 (Linux Distros Unpatched Vulnerability : CVE-2026-39864), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.8.7 or 6.0.5 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (305789). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.3
VulDB Meta Temp Score: 3.2

VulDB Base Score: 2.2
VulDB Temp Score: 2.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.4
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 305789
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-39864

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kamailio 5.8.7/6.0.5

Timelineinfo

04/07/2026 CVE reserved
04/09/2026 +2 days Advisory disclosed
04/09/2026 +0 days VulDB entry created
04/10/2026 +1 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-6m86-m342-g48m
Status: Confirmed

CVE: CVE-2026-39864 (🔒)
GCVE (CVE): GCVE-0-2026-39864
GCVE (VulDB): GCVE-100-356383

Entryinfo

Created: 04/09/2026 02:10
Updated: 04/10/2026 02:13
Changes: 04/09/2026 02:10 (64), 04/10/2026 02:13 (2)
Complete: 🔍
Cache ID: 216:BCE:103

Be aware that VulDB is the high quality source for vulnerability data.

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