CVE catalog

CVE-2019-20398

UBUNTU-CVE-2019-20398

Severity: Medium · CVSS 6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Published: Jan 22, 2020, 10:15:00 PM UTC
Updated: Sep 21, 2026, 7:03:17 AM UTC
Source: [NVD] · [CVE record]
EPSS: 1.82% · Oct 25, 2026

A NULL pointer dereference is present in libyang before v1.0-r3 in the function lys_extension_instances_free() due to a copy of unresolved extensions in lys_restr_dup(). Applications that use libyang to parse untrusted input yang files may crash.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	libyang	13	`1.0.176-1`	fixed
Debian	libyang	14	`1.0.176-1`	fixed
Ubuntu	libyang	20.04	`0.16.105-1`	vulnerable
Ubuntu	libyang	20.04	`0.16.105-2`	vulnerable
Ubuntu	libyang	20.04	`0.16.105-3`	vulnerable
Ubuntu	libyang	20.04	`0.16.105-3build1`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	libyang	deb	13	`1.0.176-1`	Not reported	DEBIAN-CVE-2019-20398	Not reported
Debian	libyang	deb	14	`1.0.176-1`	Not reported	DEBIAN-CVE-2019-20398	Not reported

OpenFactory catalog packages

[Debian 13 (Trixie)]

[libyang3]Fixed
Source package: [libyang]
Details (4)
- 3.12.2-1 · amd64 · trixie
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.12.2-1 · arm64 · trixie
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.13.6-1~bpo13+1 · amd64 · trixie-backports
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.13.6-1~bpo13+1 · arm64 · trixie-backports
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
[libyang3-tools]Fixed
Source package: [libyang]
Details (4)
- 3.12.2-1 · amd64 · trixie
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.12.2-1 · arm64 · trixie
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.13.6-1~bpo13+1 · amd64 · trixie-backports
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.13.6-1~bpo13+1 · arm64 · trixie-backports
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
[libyang-dev]Fixed
Source package: [libyang]
Details (4)
- 3.12.2-1 · amd64 · trixie
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.12.2-1 · arm64 · trixie
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.13.6-1~bpo13+1 · amd64 · trixie-backports
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13
- 3.13.6-1~bpo13+1 · arm64 · trixie-backports
  Fixed · Fixed: 1.0.176-1
  pypi · libyang · debian · 13

Observed: Oct 23, 2026, 5:43:46 PM UTC

References

[FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]