libyang - Heap Use-After-Free Write in XML Metadata Parsing (libyang libyang)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.67 % · percentile 52 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- VulnCheck
- NVD status
- Deferred
Description
libyang before 5.4.3 contains a heap use-after-free write vulnerability in lyd_parser_set_data_flags that incorrectly updates metadata list pointers when freeing non-head default metadata entries. Attackers can trigger this vulnerability by submitting crafted YANG XML documents with specific metadata attributes to applications parsing untrusted XML data, causing process crashes or potential code execution.
Weaknesses (CWE)
- CWE-416 — Use After Free
References
- https://github.com/CESNET/libyang/security/advisories/GHSA-9f49-8x56-jmjc
- https://github.com/CESNET/libyang/commit/6b5ed47ee674fbe86b31bbebc4ff26889aeff38c
- https://red.anthropic.com/2026/cvd/findings/ANT-2026-TZQ1KH7E
- https://www.vulncheck.com/advisories/libyang-heap-use-after-free-write-in-xml-metadata-parsing
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
| CVSS 4.0 | HIGH 7.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · disclosure@vulncheck.com (Secondary) |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · disclosure@vulncheck.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-31832
- GCVE · GCVE-0-2026-41401
CERT-FR advisories
- CERTFR-2026-AVI-0674 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| libyang · libyang | affected 0 < 5.4.3 ; unaffected 5.4.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |