Asterisk Decoder heap-based overflow

Summaryinfo

A vulnerability categorized as critical has been discovered in Asterisk. Affected by this issue is some unknown functionality of the component Decoder. Executing a manipulation can lead to heap-based overflow. This vulnerability is tracked as CVE-2026-57192. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical was found in Asterisk (affected version unknown). This vulnerability affects an unknown functionality of the component Decoder. The manipulation with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability was named CVE-2026-57192 since 06/24/2026. The exploitation appears to be easy. The attack can be initiated remotely. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/27/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Communications System

Name

• Asterisk

Website

• Product: https://github.com/asterisk/asterisk/

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