CVE-2021-27645: Debian Linux

Low severity, CVSS 2.5. EPSS: 0.4% chance of exploitation in the next 30 days.

The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Service on the local system. This is related to netgroupcache.c.

Affected products

• Debian Debian Linux: version 10.0 only
• Fedoraproject Fedora: version 33 only; version 34 only
• GNU Glibc: from 2.29, up to and including 2.33

Published 2021-02-24. Last modified 2026-06-17.