Out-of-bounds write in Asterisk Open Source and Certified Asterisk - CVE-2026-57194
Published: June 26, 2026
Vulnerability identifier: #VU135557
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-57194
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to out-of-bounds write in the chan_unistim DIALPAGE digit handling for the phone_number buffer when processing a crafted incoming UNISTIM request packet. A remote user can send a carefully crafted incoming request packet to cause a denial of service.
The chan_unistim module must be loaded and configured with a valid UNISTIM UDP port, and exploitation requires registering as a configured phone MAC or using an equivalent provisioning path that allows a client to reach the main page.
Affected software
Asterisk Open Source
Certified Asterisk
Certified Asterisk
How to mitigate CVE-2026-57194
Install security update from vendor's website.
Asterisk Open Source - addressed in versions 20.20.1, 21.12.3, 22.10.1, 23.4.1
Certified Asterisk - addressed in versions 20.7-cert11, 22.8-cert3
Certified Asterisk - addressed in versions 20.7-cert11, 22.8-cert3