Reachable assertion in libyang - #VU165955
Published: November 12, 2026
Vulnerability identifier: #VU165955
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-617
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a reachable assertion caused by missing descendant schema-nodeid prefix validation in libyang's lysp_schema_nodeid_match processing when compiling refine targets with unrecognized module prefixes. A remote attacker can supply a crafted YANG module containing refine "invalid:my-leaf" to trigger assert(mod) and terminate the parsing process in a debug build.
Affected software
libyang
Remediation
Install security update from vendor's website.
libyang - update to 5.2.0