PT-2026-52209 · Nlnet · Nsd

Qifan Zhang · Published 2026-06-25 · Updated 2026-06-25 · CVE-2026-12244

NVD

CVSS v4.0

8.7

High

Base vector

AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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

Fix

Integer Overflow

Heap Based Buffer Overflow

Weakness Enumeration

CWE-190

CWE-122

Related Identifiers

CVE-2026-12244

Affected Products

Nsd

References · 2

• https://nlnetlabs.nl/downloads/nsd/CVE-2026-12244.txt · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-12244 · Security Note