Description
Asterisk is an open-source private branch exchange (PBX). Prior to versions 18.26.2, 20.14.1, 21.9.1, and 22.4.1 of Asterisk and versions 18.9-cert14 and 20.7-cert5 of certified-asterisk, SIP requests of the type MESSAGE (RFC 3428) authentication do not get proper alignment. An authenticated attacker can spoof any user identity to send spam messages to the user with their authorization token. Abuse of this security issue allows authenticated attackers to send fake chat messages can be spoofed to appear to come from trusted entities. Even administrators who follow Security best practices and Security Considerations can be impacted. Therefore, abuse can lead to spam and enable social engineering, phishing and similar attacks. Versions 18.26.2, 20.14.1, 21.9.1, and 22.4.1 of Asterisk and versions 18.9-cert14 and 20.7-cert5 of certified-asterisk fix the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| asterisk | asterisk | < 18.9-cert14, >= 18.10, < 18.26.2, >= 20.0, < 20.7-cert5, >= 20.8, < 20.14.1, >= 21.0, < 21.9.1, >= 22.0, < 22.4.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | asterisk | 1:22.4.1~dfsg+~cs6.15.60671435-1 | — |
| Debian 11 | asterisk | 1:16.28.0~dfsg-0+deb11u7 | DLA-4206-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | asterisk | No fix yet | — |
| Ubuntu 26.04 LTS | asterisk | No fix yet | — |
| Ubuntu 25.10 | asterisk | No fix yet | — |
| Ubuntu 24.04 LTS | asterisk | No fix yet | — |
| Ubuntu 22.04 LTS | asterisk | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | asterisk | No fix yet | — |
| Ubuntu 18.04 LTS | asterisk | No fix yet | — |
| Ubuntu Pro 16.04 LTS | asterisk | No fix yet | — |
Advisories 2
- WID-SEC-2025-1135 Asterisk: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 12, 2026
- DLA-4206-1 asterisk - security update Debian Security (DSA / DLA) · Mar 9, 2026