CVE-2026-57191
Published:October 27, 2026
Updated:October 28, 2026
Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, an unbounded "sscanf" in "res_pjsip_pubsub" when parsing the "MWI NOTIFY" "Message-Account" field may allow an unauthenticated attacker to send a carefully crafted packet that causes a stack buffer overflow and corrupts the underlying transport, permanently disabling all SIP functionality. An Asterisk restart is required to restore full operation. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.
Affected Packages
https://github.com/asterisk/asterisk.git (GITHUB):
Affected version(s) >=22.0.0-rc1 <22.10.1Fix Suggestion:
Update to version 22.10.1https://github.com/asterisk/asterisk.git (GITHUB):
Affected version(s) >=certified-20.7-cert1-rc1 <certified-20.7-cert11Fix Suggestion:
Update to version certified-20.7-cert11https://github.com/asterisk/asterisk.git (GITHUB):
Affected version(s) >=21.0.0-rc1 <21.12.3Fix Suggestion:
Update to version 21.12.3https://github.com/asterisk/asterisk.git (GITHUB):
Affected version(s) >=23.0.0-rc1 <23.4.1Fix Suggestion:
Update to version 23.4.1https://github.com/asterisk/asterisk.git (GITHUB):
Affected version(s) >=20.0.0-rc1 <20.20.1Fix Suggestion:
Update to version 20.20.1https://github.com/asterisk/asterisk.git (GITHUB):
Affected version(s) >=certified-22.8-cert1-rc1 <certified-22.8-cert3Fix Suggestion:
Update to version certified-22.8-cert3Related Resources (15)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH