CVE-2026-19538

EUVD-2026-66376
The BLOCKED access control list items that are evaluated to deny access on the the proxy protocol port can be bypassed completely when connecting over TCP or TLS and sending the query twice on connection that is kept open.
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:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 13.02%
Affected Products (NVD)
VendorProductVersion
nlnetlabsnsd
4.8.0 ≤
𝑥
< 4.15.1
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
nsd
bookworm
vulnerable
forky
4.15.2-1
fixed
sid
4.15.2-1
fixed
trixie
vulnerable
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
nsd
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
resolute
needs-triage
xenial
needs-triage
Common Weakness Enumeration
References
https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-19538.txt