CVE-2026-57198
Received Received - Intake

Heap Buffer Overflow in Asterisk via T.140 RED

Vulnerability report for CVE-2026-57198, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

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. In affected deployments, an authenticated attacker may cause a `T.140 RED` heap buffer overflow using carefully crafted packets, potentially allowing remote code execution or causing Asterisk to crash. The `chan_sip` channel driver must be installed and configured, and its `textsupport` option must be enabled; `textsupport` defaults to no. `The chan_sip driver was deprecated in Asterisk 20 and completely removed in all later versions.` Repository comparisons verify patch containment in Asterisk 20.20.1, 21.12.3, 22.10.1 and 23.4.1, and Certified Asterisk 20.7-cert11 and 22.8-cert3. The affected release-track scope remains unresolved: structured metadata includes later release tracks even though the advisory says the required `chan_sip` driver was removed there.

CVSS Scores

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Meta Information

Published
2026-10-27
Last Modified
2026-10-27
Generated
2026-10-27
AI Q&A
2026-10-27
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 6 associated CPEs
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
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KEV
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CWE ID Description
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().

Attack-Flow Graph

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Executive Summary

This vulnerability is a heap buffer overflow in Asterisk's T.140 RED handling. An authenticated attacker can exploit it by sending specially crafted packets to trigger the overflow in the chan_sip channel driver. This may lead to remote code execution or crashes. The chan_sip driver must be installed, configured, and have textsupport enabled for the attack to work.

Detection Guidance

Detection involves checking if the vulnerable chan_sip channel driver is installed and enabled with textsupport. Use Asterisk CLI commands like 'module show like chan_sip' to verify if the module is loaded. Check configuration files for textsupport enabled in sip.conf.

Impact Analysis

If exploited, this vulnerability could allow an attacker to execute arbitrary code on the system running Asterisk or cause the service to crash. This could disrupt telephony services, lead to unauthorized access, or compromise the integrity of the system.

Mitigation Strategies

Immediately upgrade Asterisk to patched versions: 20.20.1, 21.12.3, 22.10.1, 23.4.1, or Certified Asterisk 20.7-cert11 and 22.8-cert3. Disable chan_sip if not needed or ensure textsupport is disabled. If using Asterisk 20+, migrate away from chan_sip as it is deprecated and removed in later versions.

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