What’s Vulnerable › Vulnerabilities
CVE-2026-12244: Heap overflow and crash with crafted SVCB RR
- Severity: high (CVSS 8.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-06-25 · updated 2026-10-25
- Weakness: CWE-122
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
Affected products
- NLnet Labs NSD: from 4.14.0 before 4.14.3 — fixed in 4.14.3
How to fix
Upgrade to a fixed version: NLnet Labs NSD 4.14.3. Check the vendor advisory for mitigations.
References
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