CVE-2026-44673 — libyang: lyb_read_string() integer overflow → heap buffer overflow

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
CESNET / libyang	affected < SO 5.2.15

CWE

CWE-190

References

https://github.com/CESNET/libyang/security/advisories/GHSA-vw2p-pq79-92xh

ADP enrichment

CISA-ADP

No English description supplied.

https://github.com/CESNET/libyang/security/advisories/GHSA-vw2p-pq79-92xh

redhat-SADP

A flaw was found in libyang, a YANG data modeling language library. An integer overflow in the `lyb_read_string()` function can lead to a heap buffer overflow when parsing a maliciously crafted LYB binary blob. A remote attacker, by supplying this malicious LYB data to any libyang consumer (such as a NETCONF server), could trigger a crash, resulting in a denial of service (DoS), or potentially achieve arbitrary code execution through heap corruption.