CVE-2026-44673: libyang: lyb_read_string() integer overflow → heap buffer overflow
libyang is a YANG data modeling language library. Prior to SO 5.2.15, lybreadstring() in src/parserlyb.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.
Other sources
libyang: lybreadstring() integer overflow → heap buffer overflow
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
libyangto a version that resolves this vulnerability.Fixed in 5.2.15
Event History
Frequently Asked Questions
What is the severity of CVE-2026-44673?
CVE-2026-44673 is classified as a critical vulnerability due to its potential to cause a heap buffer overflow.
How do I fix CVE-2026-44673?
To fix CVE-2026-44673, upgrade libyang to version 5.2.15 or later.
What causes CVE-2026-44673?
CVE-2026-44673 is caused by an integer overflow in the lyb_read_string() function when parsing a malicious LYB binary blob.
What are the potential impacts of CVE-2026-44673?
The potential impacts of CVE-2026-44673 include arbitrary code execution and application crashes due to a heap buffer overflow.
Which versions of libyang are affected by CVE-2026-44673?
All versions of libyang prior to 5.2.15 are affected by CVE-2026-44673.