Stack-based buffer overflow in Asterisk Open Source and Certified Asterisk - CVE-2026-57188
Published: June 26, 2026
Vulnerability identifier: #VU135539
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-2026-57188
CWE-ID: CWE-121
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 stack-based buffer overflow in res_xmpp XMPP namespace prefix handling when processing carefully crafted XMPP packets. A remote user can send specially crafted XMPP packets to cause a denial of service.
The res_xmpp module must be loaded, an XMPP connection must be configured in xmpp.conf, and the attacker must have an XMPP account on the same or a federated server.
Affected software
Asterisk Open Source
Certified Asterisk
Certified Asterisk
How to mitigate CVE-2026-57188
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