CVE-2026-44673: Cesnet Libyang

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

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 products

  • Cesnet Libyang
  • Red Hat Red Hat Enterprise Linux 10: before 0:2.1.148-4.el10_2 (fixed in 0:2.1.148-4.el10_2)
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support: before 0:2.1.148-2.el10_0.1 (fixed in 0:2.1.148-2.el10_0.1)
  • Red Hat Red Hat Enterprise Linux 8: before 0:1.0.184-2.el8_10 (fixed in 0:1.0.184-2.el8_10)
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: before 0:1.0.184-1.el8_4.1 (fixed in 0:1.0.184-1.el8_4.1)
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: before 0:1.0.184-1.el8_4.1 (fixed in 0:1.0.184-1.el8_4.1)
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: before 0:1.0.184-1.el8_6.1 (fixed in 0:1.0.184-1.el8_6.1)
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: before 0:1.0.184-1.el8_6.1 (fixed in 0:1.0.184-1.el8_6.1)
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service: before 0:1.0.184-1.el8_8.1 (fixed in 0:1.0.184-1.el8_8.1)
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions: before 0:1.0.184-1.el8_8.1 (fixed in 0:1.0.184-1.el8_8.1)
  • Red Hat Red Hat Enterprise Linux 9: before 0:2.1.148-1.el9_8.1 (fixed in 0:2.1.148-1.el9_8.1)
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions: before 0:2.1.148-1.el9_2.1 (fixed in 0:2.1.148-1.el9_2.1)
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services For SAP Solutions: before 0:2.1.148-1.el9_4.1 (fixed in 0:2.1.148-1.el9_4.1)
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support: before 0:2.1.148-1.el9_6.1 (fixed in 0:2.1.148-1.el9_6.1)

Published 2026-05-14. Last modified 2026-09-09.