CVE-2026-101339
8.7HighPublished 14 Oct 2026 · NVD status: Awaiting Analysis · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Impact
- Full C/I/A compromise
- Weakness
- CWE-121
Impact
An attacker with control over ingested zone files can execute arbitrary code on the NSD server via a stack-based buffer overflow. Exploitation requires feeding a crafted zone file directly into NSD via provisioning or local file loading.
Root cause
Parsing a HIP resource record with near-limit RDATA alongside an additional dname RDATA field triggers a 191-byte stack buffer overflow.
Affected systems
Versions not listed — check the vendor advisory.
CVSS v4.0 · 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/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
Fix & remediation
Upgrade NSD to the patched release referenced in NLnet Labs advisory CVE-2026-101339.txt; as an interim workaround, sanitize or block HIP records containing rendezvous servers in zone provisioning pipelines before feeding files to NSD.
AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
A HIP resource record that fills the RDATA near or at is limit, and has another dname RDATA field (a HIP Rendezvous server) can overwrite the stack with up to 191 bytes of attacker controlled data. Zone files which are written out by NSD itself, such as for zones for which the NSD instance is secondary, will not be formatted like this. The zone file must be fed to NSD directly, (but it could come, for example, from an operator controlled provisioning system).