CVE-2026-57199

Received Received - Intake

Buffer Overflow in Asterisk SMS Dialplan Application

Publication date: 2026-10-27

Last updated on: 2026-10-27

Assigner: GitHub, Inc.

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, `app_sms.c` copies externally controlled `SMS` lengths into `fixed in-struct buffers` without sufficient bounds checks, allowing an attacker to corrupt memory or crash Asterisk. The administrator must explicitly use the `SMS` dialplan application, which is useful when routing calls to or from `analog devices`, and must not have ensured that data passed to the application is valid. 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 Scores

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Meta Information

Published

2026-10-27

Last Modified

2026-10-27

Generated

2026-10-28

AI Q&A

2026-10-28

EPSS Evaluated

N/A

NVD

CVE-2026-57199

Affected Vendors & Products

Vendor	Product	Version / Range
asterisk	asterisk	< 20.20.1
asterisk	asterisk	>= 21.0.0-pre1, < 21.12.3
asterisk	asterisk	>= 22.0.0-pre1, < 22.10.1
asterisk	asterisk	>= 23.0.0-pre1, < 23.4.1
asterisk	certified-asterisk	< 20.7-cert11
asterisk	certified-asterisk	>= 22.8-cert1-pre1, < 22.8-cert3

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

Asterisk is a telephony toolkit with a vulnerability in the SMS dialplan application. The issue occurs in app_sms.c where externally controlled SMS lengths are copied into fixed buffers without proper bounds checks. This allows attackers to corrupt memory or crash Asterisk if they can pass invalid data to the SMS application.

Detection Guidance

Detection requires checking if the vulnerable Asterisk versions are running and if the SMS dialplan application is enabled. Verify installed versions with 'asterisk -V' and check for active SMS usage in dialplan configurations. No direct commands detect exploitation but monitoring for crashes or memory corruption may indicate issues.

Impact Analysis

This vulnerability can cause Asterisk to crash or experience memory corruption if the SMS dialplan application is used with invalid data. This may lead to service disruption for telephony systems relying on Asterisk. Only systems explicitly using the SMS application and receiving untrusted input are affected.

Mitigation Strategies

Upgrade Asterisk to patched versions (20.20.1, 21.12.3, 22.10.1, 23.4.1 or Certified Asterisk 20.7-cert11, 22.8-cert3). If upgrading is not possible, disable the SMS dialplan application in configurations to prevent exploitation.

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