CVE-2026-57185: Asterisk: Buffer over-read in Asterisk PJSIP MWI body parser
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 authenticated attacker may crash Asterisk through a buffer over-read in the PJSIP MWI body parser by sending a carefully crafted SIP NOTIFY request. The attacker must pass SIP authentication using either a username/password or source IP address matching. 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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Asteriskto a version that resolves this vulnerability.Fixed in 20.20.1 - Upgrade
Upgrade
Asteriskto a version that resolves this vulnerability.Fixed in 21.12.3 - Upgrade
Upgrade
Asteriskto a version that resolves this vulnerability.Fixed in 22.10.1 - Upgrade
Upgrade
Asteriskto a version that resolves this vulnerability.Fixed in 23.4.1 - Upgrade
Upgrade
Certified Asteriskto a version that resolves this vulnerability.Fixed in 20.7-cert11 - Upgrade
Upgrade
Certified Asteriskto a version that resolves this vulnerability.Fixed in 22.8-cert3
Event History
Frequently Asked Questions
Who can exploit this issue?
An attacker must be able to authenticate to the affected Asterisk SIP service. Authentication can be satisfied with a username and password or by connecting from a source IP address that matches an allowed configuration.
What is the practical impact of successful exploitation?
A successful attack can crash Asterisk, causing a denial of service. The provided information does not indicate confidentiality or integrity impact.
Which releases contain the fix?
The issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, and 23.4.1. It is also fixed in Certified Asterisk 20.7-cert11 and 22.8-cert3.
What should be prioritized if an immediate upgrade is not possible?
Restrict SIP authentication access to trusted users and source IP addresses, since exploitation requires passing SIP authentication. Review configurations that permit authentication based on source IP address matching and limit those allowed addresses as tightly as possible.