What’s Vulnerable › Vulnerabilities
CVE-2026-23739: Asterisk xml.c uses unsafe XML_PARSE_NOENT leading to potential XXE Injection
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-02-06 · updated 2026-06-17
- Weakness: CWE-611
Description
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, the ast_xml_open() function in xml.c parses XML documents using libxml with unsafe parsing options that enable entity expansion and XInclude processing. Specifically, it invokes xmlReadFile() with the XML_PARSE_NOENT flag and later processes XIncludes via xmlXIncludeProcess().If any untrusted or user-supplied XML file is passed to this function, it can allow an attacker to trigger XML External Entity (XXE) or XInclude-based local file disclosure, potentially exposing sensitive files from the host system. This can also be triggered in other cases in which the user is able to supply input in xml format that triggers the asterisk process to parse it. This issue has been patched in versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2.
Affected products
- asterisk: before 20.18.2; from 21.0.0 before 21.12.1; from 22.0.0 before 22.8.2; from 23.0.0 before 23.2.2 — fixed in 20.18.2, 21.12.1, 22.8.2, 23.2.2
- Sangoma Certified Asterisk: through 18.9; 20.7-cert1, 20.7-cert1-rc1, 20.7-cert1-rc2, 20.7-cert2, 20.7-cert3, 20.7-cert4 (+4)
How to fix
Upgrade to a fixed version: asterisk 20.18.2, 21.12.1, 22.8.2, 23.2.2. Check the vendor advisory for mitigations.
References
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