Asterisk PBX up to 23.2.1 /tmp ast_coredumper uncontrolled search path

CVSS Meta Temp Score
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CTI Interest Score
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6.0$0-$5k0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Asterisk PBX up to 20.7-cert8/20.18.1/21.12.0/22.8.1/23.2.1. This affects the function ast_coredumper of the file /tmp. Executing a manipulation can lead to uncontrolled search path. The identification of this vulnerability is CVE-2026-23740. The attack can only be executed locally. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Asterisk PBX up to 20.7-cert8/20.18.1/21.12.0/22.8.1/23.2.1 and classified as critical. This vulnerability affects the function ast_coredumper of the file /tmp. The manipulation with an unknown input leads to a uncontrolled search path vulnerability. The CWE definition for the vulnerability is CWE-427. The product uses a fixed or controlled search path to find resources, but one or more locations in that path can be under the control of unintended actors. 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 versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2, when ast_coredumper writes its gdb init and output files to a directory that is world-writable (for example /tmp), an attacker with write permission(which is all users on a linux system) to that directory can cause root to execute arbitrary commands or overwrite arbitrary files by controlling the gdb init file and output paths. This issue has been patched in versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-23740 since 01/15/2026. The exploitation appears to be difficult. The attack needs to be approached locally. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1574.

The vulnerability scanner Nessus provides a plugin with the ID 298279 (Linux Distros Unpatched Vulnerability : CVE-2026-23740), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 20.7-cert9, 20.18.2, 21.12.1, 22.8.2 or 23.2.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (298279) and CERT Bund (WID-SEC-2026-0327). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Open Source Asterisk

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.1
VulDB Meta Temp Score: 6.0

VulDB Base Score: 7.0
VulDB Temp Score: 6.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CNA Base Score: 1.8
CNA Vector (GitHub_M): 🔒

ADP CISA Base Score: 7.8
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Uncontrolled search path
CWE: CWE-427 / CWE-426
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298279
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23740

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: PBX 20.7-cert9/20.18.2/21.12.1/22.8.2/23.2.2

Timelineinfo

01/15/2026 CVE reserved
02/06/2026 +22 days Advisory disclosed
02/06/2026 +0 days VulDB entry created
02/11/2026 +5 days VulDB entry last update

Sourcesinfo

Advisory: GHSA-xpc6-x892-v83c
Status: Confirmed

CVE: CVE-2026-23740 (🔒)
GCVE (CVE): GCVE-0-2026-23740
GCVE (VulDB): GCVE-100-344704
CERT Bund: WID-SEC-2026-0327 - Asterisk: Mehrere Schwachstellen

Entryinfo

Created: 02/06/2026 21:14
Updated: 02/11/2026 08:42
Changes: 02/06/2026 21:14 (67), 02/07/2026 05:14 (7), 02/07/2026 09:22 (1), 02/07/2026 11:50 (2), 02/11/2026 08:42 (20)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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