CVE-2026-12244CWE-122CWE-190

Heap overflow and crash with crafted SVCB RR

High · published June 25, 2026

CVSS v4.0
8.7
EPSS
0%
Percentile
41.0
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v4.0
8.7 · HIGH
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
0.00487 · 41.0th percentile
Weaknesses
CWE-122 · Heap-based Buffer Overflow; CWE-190 · Integer Overflow or Wraparound
Published
2026-06-25T05:24Z
EPSS history
Timeline
  • 25 JUN 05:24Z
    Heap overflow and crash with crafted SVCB RR
    cvelistv5