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OpenAdvisories
Medium · 6.0 CVE-2026-57192 EUVD-2026-111396

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

Published Oct 27, 2026 · Updated Nov 3, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
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.

ReleasePackageFixed inAdvisory
Debian 14 asterisk 1:22.10.1+dfsg+~cs6.17.60671434-1 —
ReleasePackageFixed inAdvisory
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)
ReleasePackageFixed inAdvisory
Ubuntu 18.04 LTS asterisk No fix yet —
Ubuntu Pro 16.04 LTS asterisk No fix yet —

Advisories 1

References