A stack-based buffer overflow exists in Kamailio v6.1.3 and v6.1.4 in the ims_qos_npn module.

published 2026-11-02 8d ago modified 2026-11-02 7d ago also EUVD-2026-115345

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits: 0; none known

A stack-based buffer overflow exists in Kamailio v6.1.3 and v6.1.4 in the ims_qos_npn module. 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. An unauthenticated remote attacker can trigger the vulnerability with a crafted SIP `REGISTER` request, causing stack corruption and termination of the affected Kamailio instance, resulting in denial of service.

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CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 7d ago (2026-11-02)

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

github.com https://github.com/kamailio/kamailio/issues/4953 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness

CWE-121 Stack-based Buffer Overflow
CWE-120 Buffer Copy without Checking Size of Input
CWE-20 Improper Input Validation

References

Sources

CVE List CVE-2026-106804
NVD CVE-2026-106804

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