CVE-2026-12245

EUVD-2026-39183
NSD from version 4.13.0 has a heap use-after-free bug in logging errors on TLS connections, causing a crash of the server process, which can be triggered trivially by sending a DNS query over a DoT connection, and closing the connection without reading the response.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 24.34%
Affected Products (NVD)
VendorProductVersion
nlnetlabsnsd
4.13.0 ≤
𝑥
< 4.14.3
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
nsd
bookworm
4.6.1-1
fixed
bullseye
4.3.5-1
fixed
forky
4.15.0-1
fixed
sid
4.15.0-1
fixed
trixie
4.12.0-1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
nsd
bionic
not-affected
focal
not-affected
jammy
not-affected
noble
not-affected
questing
ignored
resolute
Fixed 4.14.0-1ubuntu0.1~esm1
released
Common Weakness Enumeration
References
https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-12245.txt