CVE catalog

CVE-2021-28906

libyang2: CVE-2021-28906

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: May 20, 2021, 7:15:00 PM UTC
Source: [NVD] · [CVE record]
EPSS: 1.57% · Oct 25, 2026

In function read_yin_leaf() in libyang <= v1.0.225, it doesn't check whether the value of retval->ext[r] is NULL. In some cases, it can be NULL, which leads to the operation of retval->ext[r]->flags that results in a 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	libyang2	bookworm	`2.1.30-2`	not affected
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
Ubuntu	libyang	22.04	`1.0.225-1.1`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	libyang2	source	bookworm	`Not affected`	unimportant	Not reported	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libyang2]Not affected
Details (2)
- 2.1.30-2 · amd64 · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm
- 2.1.30-2 · arm64 · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm
[libyang2-dev]Not affected
Source package: [libyang2]
Details (2)
- 2.1.30-2 · amd64 · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm
- 2.1.30-2 · arm64 · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm
[libyang2-tools]Not affected
Source package: [libyang2]
Details (2)
- 2.1.30-2 · amd64 · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm
- 2.1.30-2 · arm64 · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm
[libyang-tools]Not affected
Source package: [libyang2]
Details (2)
- 2.1.30-2 · all · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm
- 2.1.30-2 · all · bookworm
  Not affected
  dsa · libyang2 · debian · bookworm

[Debian 13 (Trixie)]

[libyang3]Fixed
Source package: [libyang]
Details (4)
- 3.12.2-1 · amd64 · trixie
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.12.2-1 · arm64 · trixie
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.13.6-1~bpo13+1 · amd64 · trixie-backports
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.13.6-1~bpo13+1 · arm64 · trixie-backports
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
[libyang3-tools]Fixed
Source package: [libyang]
Details (4)
- 3.12.2-1 · amd64 · trixie
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.12.2-1 · arm64 · trixie
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.13.6-1~bpo13+1 · amd64 · trixie-backports
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.13.6-1~bpo13+1 · arm64 · trixie-backports
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
[libyang-dev]Fixed
Source package: [libyang]
Details (4)
- 3.12.2-1 · amd64 · trixie
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.12.2-1 · arm64 · trixie
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.13.6-1~bpo13+1 · amd64 · trixie-backports
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13
- 3.13.6-1~bpo13+1 · arm64 · trixie-backports
  Fixed · Fixed: 3.4.2+dfsg-2
  dsa · libyang · debian · 13

Observed: Oct 23, 2026, 5:55:52 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]