Medium severity · published Oct 27, 2026
CVE-2026-57194
Asterisk: chan_unistim DIALPAGE digit handling can overflow phone_number and crash Asterisk
New
5.9
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
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 · source: vendor
CE
certified-asterisk · asterisk
< 20.7-cert11; >= 22.8-cert1-pre1, < 22.8-cert3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-57194
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-57194
github.com
https://github.com/asterisk/asterisk/commit/430f423c84e4e32a462d907632b66c9793236e96
github.com
https://github.com/asterisk/asterisk/commit/6da8e10c210d8e014c27c67235252e1dfc794446
github.com
https://github.com/asterisk/asterisk/commit/6f414ec771eaa3318a4b2d28f70fa387196ae283
github.com
https://github.com/asterisk/asterisk/commit/ce6e2233599b76bc30c33b4816b15609c8ddc8b6
github.com
https://github.com/asterisk/asterisk/commit/d803b5370b05f39a6241b2556eb9894b02148e6a
github.com
https://github.com/asterisk/asterisk/commit/fc3a1cb3c386c962bfca8cd9d533d1390d4ad933
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