Main Vulnerability Database Vulnerabilities #VU146773

Memory leak in SIP IP Phone Software - CVE-2026-20281

Published: September 2, 2026

Vulnerability identifier: #VU146773

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-20281

CWE-ID: CWE-401

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper memory management in web access handling when processing HTTP packets. A remote attacker can send a continuous stream of crafted HTTP packets to cause a denial of service.

The device must be registered to Cisco Unified Communications Manager and have Web Access enabled. A manual reboot is required to recover from the condition.

Affected software

SIP IP Phone Software

How to mitigate CVE-2026-20281

Install security update from vendor's website.

SIP IP Phone Software - addressed in versions 5.0(1), 11.0(6)SR8, 14.4(1)SR3, 14.4(1)SR4

External References

Related Security Bulletins