CVE-2026-23740
Sangoma Certified Asterisk 13.13.0 … 20.7
Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:NSummary
CVE-2026-23740 is a uncategorised-severity Uncontrolled Search Path Element (CWE-427) vulnerability in Sangoma Certified Asterisk. Its CVSS base score is 0.0.
Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-23740 is a vulnerability in Asterisk, an open source private branch exchange and telephony toolkit. It affects the ast_coredumper component, which writes gdb init and output files to world-writable directories such as /tmp in versions prior to 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2. The flaw, classified as CWE-427 (Untrusted Search Path), allows manipulation of these file paths when the directory permits writes from unprivileged users.
Any local user on a Linux system with write access to the target directory, such as /tmp, can exploit the vulnerability. By controlling the gdb init file and output paths, the attacker can trick the root-privileged ast_coredumper into executing arbitrary commands or overwriting arbitrary files. The CVSS v3.1 base score is 0.0 (AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:N), indicating a local attack with low complexity, no privileges required, user interaction needed, and changed scope but no direct confidentiality, integrity, or availability impact.
The official Asterisk security advisory at https://github.com/asterisk/asterisk/security/advisories/GHSA-xpc6-x892-v83c confirms the issue has been addressed in versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2. Practitioners should upgrade affected installations to these patched releases to prevent exploitation.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-5617
Vulnerability Data
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…
more
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
- 2 hardening rules · 1 OS baseline
—
Mitigating Controls (NIST 800-53 r5) AI
Establishes restrictive configuration settings that can define and lock down approved search paths.
Enforces approved authorizations so that only intended actors can place or modify elements in the search path.
Limits privileges so unintended actors cannot write to or control directories in the product's search path.
Restricts logical and physical access to change system configuration, including search-path settings and directories.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices directly address design of search paths and resource loading.
Hardened configuration baselines can enforce safe search-path settings and reduce exposure.
Execution allow-listing can block malicious binaries placed in hijackable search locations.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect uncontrolled search-path issues but does not prevent them by itself.
Restricting software installation reduces the chance that an attacker-controlled path element is introduced into the search path.
Secure system architecture and engineering principles require explicit control over search paths and resource locations.
Secure coding practices directly address the use of fixed or controlled search paths that can be influenced by unintended actors.
Configuration management can enforce approved search-path settings but does not inherently prevent the weakness.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (1 rule)
- V-248577 OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks. prevents CWE-427