What is CVE-2026-106804?

CVE-2026-106804 is a high-severity security flaw with a CVSS base score of 7.5 affecting specific releases of the popular SIP server análisis de vulnerabilidades críticas.

The issue resides within the ims_qos_npn module of the software platform. For comparison regarding other severe bugs, see escalada de privilegios local and details on vulnerabilidades en componentes.

Who is affected by this vulnerability?

The security flaw affects Kamailio v6.1.3 and v6.1.4 specifically within the ims_qos_npn module implementation.

The w_rx_aar_register() function copies the attacker-controlled host field from the SIP Via header into a fixed 46-byte stack buffer without validating its length.

How does the exploit trigger a denial of service?

An unauthenticated remote attacker can trigger the vulnerability by sending a carefully crafted SIP REGISTER request to the target server.

This action causes stack corruption and immediate termination of the affected Kamailio instance, resulting in a complete denial of service.

How do I protect my system?

Protecting your SIP infrastructure requires immediate administrative measures to prevent unauthorized exploitation of the stack-based buffer overflow.

Follow these concrete mitigation steps to secure your environment against remote disruptions:

  1. Identify if your deployment is running Kamailio v6.1.3 or v6.1.4 with the ims_qos_npn module loaded.
  2. Disable the ims_qos_npn module in your configuration if it is not strictly required for your IMS architecture.
  3. Implement strict perimeter firewall rules to filter and inspect incoming SIP REGISTER requests.
  4. Monitor system logs closely for unexpected crashes or service terminations associated with stack corruption.