Vulnerability 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.
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Sangoma | Asterisk | < 20.18.2 |
| Sangoma | Certified Asterisk | <= 18.9 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-23739?
CVE-2026-23739 is a vulnerability with a CVSS score of 2.0 (LOW). 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 ...
How severe is CVE-2026-23739?
CVE-2026-23739 has been rated LOW with a CVSS base score of 2.0/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-23739?
Check the references section above for vendor advisories and patch information. Affected products include: Sangoma Asterisk, Sangoma Certified Asterisk.