CVE-2026-44673

Publication date 14 May 2026

Last updated 19 June 2026

Ubuntu priority

Cvss 3 Severity Score

Description

libyang is a YANG data modeling language library. Prior to SO 5.2.15, lyb_read_string() in src/parser_lyb.c contains an integer overflow that results in a heap buffer overflow when parsing a maliciously crafted LYB binary blob. An attacker who can supply LYB data to any libyang consumer (NETCONF server, sysrepo, etc.) can trigger a crash or potential heap corruption. This vulnerability is fixed in SO 5.2.15.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libyang	26.04 LTS resolute	Not affected
	25.10 questing	Not affected
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
libyang2	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected

Notes

mdeslaur

The code in 3.13.6 doesn't appear to be vulnerable to this issue. Marking as not-affected.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libyang	Upstream: 73da1db

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H