CVE-2026-57192: Asterisk: Out-of-Bounds Write in Codec2 Decoder Due to Floor/Ceil Sample Count Mismatch

Medium severity · published Oct 27, 2026

CVE-2026-57192

Asterisk: Out-of-Bounds Write in Codec2 Decoder Due to Floor/Ceil Sample Count Mismatch

New

6.0

CVSS

0.6%

EPSS

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 authenticated attacker may cause a heap buffer overflow through an out-of-bounds write in the `Codec2` decoder caused by a `floor/ceil sample-count mismatch`. The `codec_codec2` module must be loaded and `Codec2` must be configured on the attacked endpoint. The attacker must pass SIP authentication by username/password or `source IP address matching`, establish a call using `Codec2`, and send carefully crafted `Codec2` audio packets. 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.

Exploitation

Is it being used?

Exploit prediction (EPSS)0.6% · higher than 51% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which 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 · source: vendor

certified-asterisk · asterisk

< 20.7-cert11; >= 22.8-cert1-pre1, < 22.8-cert3 · source: vendor