Description
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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| asterisk | asterisk | < 20.20.1, >= 21.0.0-pre1, < 21.12.3, >= 22.0.0-pre1, < 22.10.1, >= 23.0.0-pre1, < 23.4.1 | — |
| asterisk | certified-asterisk | < 20.7-cert11, >= 22.8-cert1-pre1, < 22.8-cert3 | — |
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 | 1:22.10.1+dfsg+~cs6.17.60671434-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | asterisk | No fix yet | — |
| Ubuntu 26.04 LTS | asterisk | No fix yet | — |
| Ubuntu 24.04 LTS | asterisk | No fix yet | — |
| Ubuntu 22.04 LTS | asterisk | No fix yet | — |
| Ubuntu 20.04 LTS | asterisk | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | asterisk | No fix yet | — |
| Ubuntu Pro 16.04 LTS | asterisk | No fix yet | — |
Advisories 1
- WID-SEC-2026-4205 Asterisk: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 4, 2026
References
- https://github.com/asterisk/asterisk/security/advisories/GHSA-589g-qgf8-m6mx
- https://github.com/asterisk/asterisk/commit/0e89514084490070c5ecee419ec5ee37b7c49528
- https://github.com/asterisk/asterisk/commit/647b35c3cfd4a2cc3b1fb7560b085feba5c24b4b
- https://github.com/asterisk/asterisk/commit/7a1ffcdf38cc76d1c4eae51651667f3fd4548ab0
- https://github.com/asterisk/asterisk/commit/b4be3bd67ce4ac35b94fbfa860cdd9e1c906610b
- https://github.com/asterisk/asterisk/commit/b5281828dad7d44658439ba6393fe6be3328a4bd
- https://github.com/asterisk/asterisk/commit/dca516f6d895e8867d48fa56b6ce7f05b6f7457a
- https://github.com/asterisk/asterisk/commit/ee1b66a5e40733ba0b9fad7fc4d032cabbe1dd75
- https://github.com/asterisk/asterisk/releases/tag/20.20.1
- https://github.com/asterisk/asterisk/releases/tag/21.12.3
- https://github.com/asterisk/asterisk/releases/tag/22.10.1
- https://github.com/asterisk/asterisk/releases/tag/23.4.1
- https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11
- https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3
- https://github.com/asterisk/asterisk/tree/24.0.0-pre1