Out-of-bounds read in libyang - #VU163176
Published: November 9, 2026
Vulnerability identifier: #VU163176
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows an unauthenticated attacker to crash applications that parse attacker-controlled JSON with libyang, causing denial of service.
The vulnerability exists due to an out-of-bounds heap read in libyang's JSON metadata processing when a metadata block precedes its corresponding data node and contains a schema-recognized child. An unauthenticated attacker can supply such malformed JSON to the public lyd_parse_data() API and trigger a segmentation fault.
Affected software
libyang
Remediation
Install security update from vendor's website.
libyang - update to 5.8.6