---
id: CVE-2026-106803
title: >-
  A stack-based buffer overflow exists in Kamailio v6.1.3 and v6.1.4 in the
  ims_registrar_pcscf module
summary: >-
  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 a…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: adp
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-11-03T13:31:38.995410Z'
exploitAvailable: true
published: '2026-11-02'
updated: '2026-11-03'
sourceUpdated: '2026-11-03T13:33:16.962Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-106803'
references:
  - url: 'https://github.com/kamailio/kamailio/issues/4954'
  - url: 'https://github.com/kamailio/kamailio/pull/4958'
  - url: >-
      https://github.com/kamailio/kamailio/commit/21261436492f0014930e804e20586e3833bb91b9
  - url: 'https://gist.github.com/hackeryounow/7d7ccc9ec501a5d8c9143b2e1bcc11cb'
tags:
  - cve.org
  - exploit-available
epss: 0.00505
epssPercentile: 0.43416
ingestedAt: '2026-11-05T19:30:42.949Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.