Review reviewHigh

CVE-2026-44673

CESNET libyang, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8

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.

CVSS: 7.5
EPSS: 0.43%
CISA KEV: Not listed
Published: 2026.05.15

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.43%

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: CESNET libyang, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8
Affected versions: >= < SO 5.2.15
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that CESNET libyang, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE: CWE-190