Kamailio 6.1.3/6.1.4 ims_registrar_pcscf process_contact alias stack-based overflow

Summaryinfo

A vulnerability labeled as critical has been found in Kamailio 6.1.3/6.1.4. Affected by this issue is the function process_contact of the component ims_registrar_pcscf. The manipulation of the argument alias results in stack-based overflow. This vulnerability is identified as CVE-2026-106803. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Kamailio 6.1.3/6.1.4. It has been classified as critical. Affected is the function process_contact of the component ims_registrar_pcscf. The manipulation of the argument alias with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on integrity, and availability. CVE summarizes:

A stack-based buffer overflow exists in Kamailio v6.1.3 and v6.1.4 in the ims_registrar_pcscf module. When processing a crafted application/reginfo+xml NOTIFY message, process_contact() copies an attacker-controlled port value from the alias parameter into a fixed 5-byte stack buffer without validating its length. An unauthenticated remote attacker can trigger stack corruption and terminate the P-CSCF process, resulting in denial of service.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-106803 since 10/07/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/02/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-115344). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

• Kamailio

Version

• 6.1.3
• 6.1.4

Website

• Product: https://github.com/kamailio/kamailio/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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