nsd-checkzone in NLnet Labs NSD 4.2.0 has a Stack-based Buffer Overflow in the dname_concatenate() function in dname.c.

published 2019-07-03 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-4728

cvss: 9.8; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 2.0%; EPSS 2.0% chance of exploitation in 30 days, percentile 81%
public exploits: 0; none known

Patch / fix

distros 2

debian opensuse

nsd Debian 14, Debian 13, Debian 12 4.2.4-1

debian advisories DEBIAN-CVE-2019-13207

nsd openSUSE Tumbleweed 4.3.7-1.2
nsd Package Hub 15 SP2, Package Hub 15 SP1, Package Hub 12 +2 more 4.3.4-bp152.2.3.1

opensuse advisories openSUSE-SU-2024:11100-1 openSUSE-SU-2020:2222-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-13207 updated 2025-11-21 cvss 6.5

nsd: stack-based overflow in function dname_concatenate() in dname.c

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.03% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/NLnetLabs/nsd/issues/20 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-787 Out-of-bounds Write

References

github.com /NLnetLabs/nsd/issues/20
exploit, third-party-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/FDS4H7WVHQGCX3LF72F5K22VJXN7HDBB/
vendor-advisory

Sources

CVE List CVE-2019-13207
NVD CVE-2019-13207

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary