CVE-2026-57188: Asterisk: Stack buffer overflow in res_xmpp XMPP namespace prefix handling
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 cause a stack buffer overflow in resxmpp XMPP namespace prefix handling using carefully crafted packets. The resxmpp 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. 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
Which deployments are exposed to this issue?
A deployment is exposed only if the res_xmpp module is loaded and an XMPP connection is configured in xmpp.conf. Systems without that module loaded or without an XMPP connection configured do not meet the stated exposure conditions.
What access does an attacker need?
The attacker must be authenticated and have an XMPP account on the same XMPP server or on a federated server. Exploitation requires sending carefully crafted XMPP packets.
What versions 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.