NSD vulnerabilities

It was discovered that NSD incorrectly handled APL resource records with an
address length larger than permitted for the address family. A remote attacker
could use this to cause a stack-based buffer overflow when the zone is written
to disk, potentially executing arbitrary code with the privileges of the NSD
server. (CVE-2026-12246)

It was discovered that NSD incorrectly handled SVCB resource records. A remote
attacker could use this to cause a heap overflow, potentially executing
arbitrary code with the privileges of the NSD server. This issue only affected
Ubuntu 26.04 LTS. (CVE-2026-12244)

It was discovered that NSD had a use-after-free vulnerability in TLS
connection error logging. A remote attacker could use this to cause a denial
of service by crashing the server process. This issue only affected Ubuntu
26.04 LTS. (CVE-2026-12245)

It was discovered that NSD incorrectly handled TLS authentication for zone
transfers. An attacker could bypass transfer security restrictions when
certain conditions were met. This issue only affected Ubuntu 26.04 LTS.
(CVE-2026-12490)