High File handling

CVE-2026-23740 — Asterisk vulnerable to potential privilege escalation

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.

Published Feb 6, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.1% (30-day exploitation probability)+0
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.13%

ahead of 2% of scored CVEs · Oct 14, 2026

Affects

Asterisk

Asterisk and 1 more

CVSS base

7.8

High · 5 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Asterisk Asterisk, Sangoma Asterisk, Sangoma Certified Asterisk).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Exploitation requires user interaction: tighten email/web filtering and warn affected users.
Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Asterisk	Asterisk	version < 20.7-cert9version < 20.18.2version < 21.12.1version < 22.8.2version < 23.2.2	Vulnerable	CVE Program (cve.org) e CISA ADP
Sangoma	Asterisk	≥ 21.0.0 and < 21.12.1< 20.18.2≥ 22.0.0 and < 22.8.2≥ 23.0.0 and < 23.2.2	Vulnerable	NIST National Vulnerability Database
Sangoma	Certified Asterisk	version 18.9-cert6version 18.9version 18.9-cert5version 18.9-cert4version 18.9-cert3version 18.9-cert2version 18.9-cert16version 18.9-cert15 and 58 more version 18.9-cert14version 18.9-cert13version 18.9-cert12version 18.9-cert11version 18.9-cert10version 18.9-cert1-rc1version 18.9-cert1version 16.8.0-cert9version 18.9-cert7version 18.9-cert8version 18.9-cert8-rc1version 18.9-cert8-rc2version 18.9-cert9version 20.7-cert1version 20.7-cert1-rc1version 20.7-cert1-rc2version 20.7-cert2version 20.7-cert3version 20.7-cert4version 20.7-cert5version 20.7-cert6version 20.7-cert7version 13.13.0-cert1version 13.13.0version 16.8-cert1-rc1version 16.8-cert13version 16.8-cert12version 16.8-cert11version 16.8-cert10version 16.8-cert1-rc5version 16.8-cert1-rc4version 16.8-cert1-rc3version 16.8-cert1-rc2version 16.8-cert14version 13.13.0-rc2version 13.13.0-rc1version 13.13.0-cert3version 13.13.0-cert2version 13.13.0-cert1-rc4version 13.13.0-cert1-rc3version 13.13.0-cert1-rc2version 16.8.0-cert11version 16.8.0-cert8version 16.8.0-cert7version 16.8.0-cert6version 16.8.0-cert5version 16.8.0-cert4version 16.8.0-cert3version 16.8.0-cert2version 16.8.0-cert12version 13.13.0-cert1-rc1version 16.8.0-cert10version 16.8.0-cert1version 16.8.0version 16.8-cert4-rc4version 16.8-cert4-rc3version 16.8-cert4-rc2version 16.8-cert4-rc1	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

None

User interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.8	CVSS 3.1	High	1.8	5.9	nvd@nist.gov via NIST National Vulnerability Database
7.8	CVSS 3.1	High	1.8	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
7.8	CVSS 3.1	High	—	—	CISA-ADP via CVE Program (cve.org) e CISA ADP
0.0	CVSS 3.1	None	1.8	0.0	security-advisories@github.com via NIST National Vulnerability Database
0.0	CVSS 3.1	None	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 7.8 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-427 · Uncontrolled Search Path Element

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.13%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Monitor file creation in web directories and paths with traversal sequences (../).

endpoint telemetry (EDR)file integrity (FIM)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · asterisk/asterisk
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 7.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Feb 6, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

github.com/asterisk/asterisk/security/advisories/GHSA-xpc6-x892-v83c
Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database

Elsewhere on this site

Asterisk
every CVE for this vendor

File handling
same class

CWE-427
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-23738 The Asterisk embedded web server 's /httpstatus page echos user supplied values(cookie and query string) without sanitization Feb 6, 2026
Medium CVE-2026-23739 Asterisk xml.c uses unsafe XML_PARSE_NOENT leading to potential XXE Injection Feb 6, 2026
High CVE-2026-23741 ast_coredumper running as root sources ast_debug_tools.conf from /etc/asterisk; potentially leading to privilege escalation Feb 6, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-23740 is "Asterisk vulnerable to potential privilege escalation", rated High. It affects Asterisk (Asterisk); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.13% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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