Vulnerability Details CVE-2026-12244
If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an (uint16_t) variable that is used to allocate space needed for the RR wrap (because total size > 65535), causing a heap overflow. The attacker can perform a controlled (RCE class) head write of up to 65509 bytes
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 22.0%
CVSS Severity
CVSS v3 Score 8.8