Description
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
Severity (CVSS)
| Base score | 8.7 |
|---|---|
| Severity | High |
| Version | CVSS 4.0 |
| 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 |
| Provided by | CNA |
Weaknesses
- CWE-190 — CWE-190: Integer Overflow or Wraparound
- CWE-122 — CWE-122: Heap-based Buffer Overflow
Affected products
| Vendor | Product | Versions |
|---|---|---|
| NLnet Labs | NSD | 4.14.0 to <4.14.3 |
References
- https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-12244.txt (vendor-advisory)
Generated from the official CVE List on 25 Jun 2026 10:14 UTC.