CVE-2026-12245
Denial of DNS over TLS service by any DoT client
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Denial of DNS over TLS service by any DoT client
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.
- Record
CVE-2026-12245- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-416
- Updated
- 2026-11-02
EUVDEUVD-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.
- Record
EUVD-2026-39183- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-rcp9-2p4r-m2hm
NSD from version 4.13.0 has a heap use-after-free bug in logging errors on TLS connections,...
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.
- Record
GHSA-rcp9-2p4r-m2hm- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-12245- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
OSVALPINE-CVE-2026-12245
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.
- Record
ALPINE-CVE-2026-12245- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSV
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.
- Record
CVE-2026-12245- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVDEBIAN-CVE-2026-12245
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.
- Record
DEBIAN-CVE-2026-12245- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-12245
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.
- Record
UBUNTU-CVE-2026-12245- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11395-1 No score
nsd-4.14.3-1.1 on GA media
These are all security issues fixed in the nsd-4.14.3-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11395-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:21502-1 No score
Security update for nsd
This update for nsd fixes the following issues:
Changes in nsd:
-
Update nsd.keyring
-
update to 4.14.3: https://github.com/NLnetLabs/nsd/blob/NSD_4_14_3_REL/doc/ChangeLog
- CVE-2026-12490: Bypass of client certificate verification with transfer over TLS (bsc#1269563)
- CVE-2026-12246: Out of bounds stack write with crafted APL RR (bsc#1269564)
- CVE-2026-12245: Denial of DNS over TLS service by any DoT client (bsc#1269565)
- CVE-2026-12244: Heap overflow and crash with crafted SVCB RR (bsc#1269566)
-
update to 4.14.2: https://github.com/NLnetLabs/nsd/blob/NSD_4_14_2_REL/doc/ChangeLog
-
update to 4.14.1: https://github.com/NLnetLabs/nsd/blob/NSD_4_14_1_REL/doc/ChangeLog
-
update to 4.14.0: https://github.com/NLnetLabs/nsd/blob/NSD_4_14_0_REL/doc/ChangeLog
-
update to 4.13.0: https://github.com/NLnetLabs/nsd/blob/NSD_4_13_0_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_12_1_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_12_0_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_11_1_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_11_0_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_10_1_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_10_0_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_9_1_REL/doc/ChangeLog https://github.com/NLnetLabs/nsd/blob/NSD_4_9_0_REL/doc/ChangeLog
-
enable systemd notify support.
-
enable dnstap support.
-
enable tcp fast open support
-
enable support for >= 2038
- Record
openSUSE-SU-2026:21502-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nsdAlpine:v3.24 |
4.13.0 up to 4.14.3-r0 | 4.14.3-r0 |
nsdDebian:14 |
before 4.14.3-1, plus listed versions 4.12.0-14.12.0-24.13.0-14.13.0-24.13.0-3 Show 6 moreShow less4.13.0-44.13.0-54.13.0-64.14.0-14.14.1-14.14.2-1 |
4.14.3-1 |
nsdUbuntu:25.10 |
All versions, plus listed versions 4.11.1-14.12.0-1 |
None known |
nsdUbuntu:26.10 |
All versions, plus listed versions 4.14.0-14.14.2-14.14.3-14.15.0-14.15.0-1build1 |
None known |
nsdUbuntu:Pro:26.04:LTS |
before 4.14.0-1ubuntu0.1~esm1, plus listed versions 4.12.0-14.13.0-64.14.0-1 |
4.14.0-1ubuntu0.1~esm1 |
nsdopenSUSE:Tumbleweed From an advisory covering 4 CVEs |
before 4.14.3-1.1 | 4.14.3-1.1 |
nsdopenSUSE:Leap 16.0 From an advisory covering 4 CVEs |
before 4.14.3-bp160.1.1 | 4.14.3-bp160.1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-12245 is a high vulnerability (CVSS 8.7) in Nlnet Labs Nsd, published June 25, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.46%, the 40th percentile. Fixed in nsd 4.14.3-r0.
References
nlnetlabs.nl/downloads/nsd/CVE-2026-12245.txt
nvd.nist.gov/vuln/detail/CVE-2026-12245
github.com/advisories/GHSA-rcp9-2p4r-m2hm
security.alpinelinux.org/vuln/CVE-2026-12245
security-tracker.debian.org/tracker/CVE-2026-12245
ubuntu.com/security/CVE-2026-12245
Show 10 moreShow less
cve.org/CVERecord?id=CVE-2026-12245
suse.com/security/cve/CVE-2026-12244
bugzilla.suse.com/1269563