Vulnerability · Published Oct 27, 2026 · Assigned by GitHub_M
CVE-2026-57194Asterisk: chan_unistim DIALPAGE digit handling can overflow phone_number and crash Asterisk
Medium 5.9
In plain English
A medium-severity out-of-bounds write in asterisk from asterisk. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 out-of-bounds write in `chan_unistim` `DIALPAGE` digit handling can overflow the `phone_number` field and crash Asterisk when an attacker sends a carefully crafted incoming request packet. The `chan_unistim` module must be loaded and configured with a valid `UNISTIM UDP port` that the attacker can reach. The attacker must register as a configured `phone MAC`, or the deployment must have an equivalent `production/autoprovisioning` path that allows the client to reach the main page. 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 & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | asterisk | 1:22.10.1+dfsg+~cs6.17.60671434-1 | DEBIAN-CVE-2026-57194 |
| Ubuntu:22.04:LTS | asterisk | no fix listed | UBUNTU-CVE-2026-57194 |
| Ubuntu:24.04:LTS | asterisk | no fix listed | UBUNTU-CVE-2026-57194 |
| Ubuntu:26.04:LTS | asterisk | no fix listed | UBUNTU-CVE-2026-57194 |
| Ubuntu:26.10 | asterisk | no fix listed | UBUNTU-CVE-2026-57194 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| 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 |
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/asterisk/asterisk/security/advisories/GHSA-3g56-cgrh-95p5 x_refsource_CONFIRM
- https://github.com/asterisk/asterisk/commit/430f423c84e4e32a462d907632b66c9793236e96 x_refsource_MISC
- https://github.com/asterisk/asterisk/commit/6da8e10c210d8e014c27c67235252e1dfc794446 x_refsource_MISC
- https://github.com/asterisk/asterisk/commit/6f414ec771eaa3318a4b2d28f70fa387196ae283 x_refsource_MISC
- https://github.com/asterisk/asterisk/commit/ce6e2233599b76bc30c33b4816b15609c8ddc8b6 x_refsource_MISC
- https://github.com/asterisk/asterisk/commit/d803b5370b05f39a6241b2556eb9894b02148e6a x_refsource_MISC
- https://github.com/asterisk/asterisk/commit/fc3a1cb3c386c962bfca8cd9d533d1390d4ad933 x_refsource_MISC
- https://github.com/asterisk/asterisk/commit/ff65e4b0867bee12cdcb3a6219b976ee7ee08963 x_refsource_MISC
- https://github.com/asterisk/asterisk/releases/tag/20.20.1 x_refsource_MISC
- https://github.com/asterisk/asterisk/releases/tag/21.12.3 x_refsource_MISC
- https://github.com/asterisk/asterisk/releases/tag/22.10.1 x_refsource_MISC
- https://github.com/asterisk/asterisk/releases/tag/23.4.1 x_refsource_MISC
- https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11 x_refsource_MISC
- https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3 x_refsource_MISC
- https://github.com/asterisk/asterisk/tree/24.0.0-pre1 x_refsource_MISC