Vulnerability 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
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nlnetlabs | Nsd | >= 4.14.0, < 4.14.3 |
Related Weaknesses (CWE)
References
- https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-12244.txtPatchVendor Advisory
FAQ
What is CVE-2026-12244?
CVE-2026-12244 is a vulnerability with a CVSS score of 8.8 (HIGH). 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 (ui...
How severe is CVE-2026-12244?
CVE-2026-12244 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-12244?
Check the references section above for vendor advisories and patch information. Affected products include: Nlnetlabs Nsd.