CVE-2026-81642

EUVD-2026-80291

16.09.2026, 09:17

In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	9.8 CRITICAL	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Base Score

CVSS 3.x

EPSS Score

Percentile: 61.65%

Affected Products (NVD)

Vendor	Product	Version
nlnetlabs	unbound	𝑥 < 1.26.1

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

unbound

bookworm	vulnerable
bookworm (security)	vulnerable
forky	1.26.2-1 fixed
sid	1.26.2-1 fixed
trixie	vulnerable
trixie (security)	1.26.2-0+deb13u1 fixed

Ubuntu Releases

Ubuntu Product

Codename

unbound

bionic	Fixed 1.6.7-1ubuntu2.6+esm5 released
focal	Fixed 1.9.4-2ubuntu1.11+esm2 released
jammy	Fixed 1.13.1-1ubuntu5.16 released
noble	Fixed 1.19.2-1ubuntu3.10 released
resolute	Fixed 1.24.2-1ubuntu2.3 released
trusty	Fixed 1.4.22-1ubuntu4.14.04.3+esm4 released
xenial	Fixed 1.5.8-1ubuntu1.1+esm4 released

openSUSE / SLES Releases

openSUSE Product

Release

libunbound8

suse enterprise desktop 15 SP7	1.26.1-150600.23.24.1 fixed
suse enterprise sap 15 SP4	1.26.1-150100.10.31.1 fixed
suse enterprise sap 15 SP5	1.26.1-150100.10.31.1 fixed
suse enterprise sap 15 SP6	1.26.1-150600.23.24.1 fixed
suse enterprise sap 15 SP7	1.26.1-150600.23.24.1 fixed
suse enterprise server 15 SP4	1.26.1-150100.10.31.1 fixed
suse enterprise server 15 SP5	1.26.1-150100.10.31.1 fixed
suse enterprise server 15 SP6	1.26.1-150600.23.24.1 fixed
suse enterprise server 15 SP7	1.26.1-150600.23.24.1 fixed

unbound-anchor

suse enterprise desktop 15 SP7	1.26.1-150600.23.24.1 fixed
suse enterprise sap 15 SP4	1.26.1-150100.10.31.1 fixed
suse enterprise sap 15 SP5	1.26.1-150100.10.31.1 fixed
suse enterprise sap 15 SP6	1.26.1-150600.23.24.1 fixed
suse enterprise sap 15 SP7	1.26.1-150600.23.24.1 fixed
suse enterprise server 15 SP4	1.26.1-150100.10.31.1 fixed
suse enterprise server 15 SP5	1.26.1-150100.10.31.1 fixed
suse enterprise server 15 SP6	1.26.1-150600.23.24.1 fixed
suse enterprise server 15 SP7	1.26.1-150600.23.24.1 fixed

unbound-devel

suse enterprise desktop 15 SP7	1.26.1-150600.23.24.1 fixed
suse enterprise sap 15 SP4	1.26.1-150100.10.31.1 fixed
suse enterprise sap 15 SP5	1.26.1-150100.10.31.1 fixed
suse enterprise sap 15 SP6	1.26.1-150600.23.24.1 fixed
suse enterprise sap 15 SP7	1.26.1-150600.23.24.1 fixed
suse enterprise server 15 SP4	1.26.1-150100.10.31.1 fixed
suse enterprise server 15 SP5	1.26.1-150100.10.31.1 fixed
suse enterprise server 15 SP6	1.26.1-150600.23.24.1 fixed
suse enterprise server 15 SP7	1.26.1-150600.23.24.1 fixed

Red Hat Enterprise Linux Releases

Red Hat Product

Release

python3-unbound

RHEL 8	0:1.16.2-5.14.el8_10.4 fixed
RHEL 8.8 E4S	0:1.16.2-5.el8_8.6 fixed
RHEL 8.8 TUS	0:1.16.2-5.el8_8.6 fixed
RHEL 9	0:1.24.2-3.el9_8.8 fixed

unbound

RHEL 8	0:1.16.2-5.14.el8_10.4 fixed
RHEL 8.4 AUS	0:1.7.3-15.el8_4.4 fixed
RHEL 8.6 AUS	0:1.7.3-17.el8_6.8 fixed
RHEL 8.8 E4S	0:1.16.2-5.el8_8.6 fixed
RHEL 8.8 TUS	0:1.16.2-5.el8_8.6 fixed
RHEL 9	0:1.24.2-3.el9_8.8 fixed

unbound-devel

RHEL 8	0:1.16.2-5.14.el8_10.4 fixed
RHEL 8.8 E4S	0:1.16.2-5.el8_8.6 fixed
RHEL 8.8 TUS	0:1.16.2-5.el8_8.6 fixed
RHEL 9	0:1.24.2-3.el9_8.8 fixed

unbound-dracut

RHEL 9

0:1.24.2-3.el9_8.8

fixed

unbound-libs

RHEL 8	0:1.16.2-5.14.el8_10.4 fixed
RHEL 8.4 AUS	0:1.7.3-15.el8_4.4 fixed
RHEL 8.6 AUS	0:1.7.3-17.el8_6.8 fixed
RHEL 8.8 E4S	0:1.16.2-5.el8_8.6 fixed
RHEL 8.8 TUS	0:1.16.2-5.el8_8.6 fixed
RHEL 9	0:1.24.2-3.el9_8.8 fixed

Amazon Linux Releases

Amazon Package

Release

python2-unbound

Amazon Linux 2

0:1.7.3-15.amzn2.0.16

fixed

python3-unbound

Amazon Linux 2	0:1.7.3-15.amzn2.0.16 fixed
Amazon Linux 2023	0:1.17.1-1.amzn2023.0.14 fixed

python3-unbound-debuginfo

Amazon Linux 2023

0:1.17.1-1.amzn2023.0.14

fixed

unbound

Amazon Linux 2	0:1.7.3-15.amzn2.0.16 fixed
Amazon Linux 2023	0:1.17.1-1.amzn2023.0.14 fixed

unbound-anchor

Amazon Linux 2023

0:1.17.1-1.amzn2023.0.14

fixed

unbound-anchor-debuginfo

Amazon Linux 2023

0:1.17.1-1.amzn2023.0.14

fixed

unbound-debuginfo

Amazon Linux 2	0:1.7.3-15.amzn2.0.16 fixed
Amazon Linux 2023	0:1.17.1-1.amzn2023.0.14 fixed

unbound-debugsource

Amazon Linux 2023

0:1.17.1-1.amzn2023.0.14

fixed

unbound-devel

Amazon Linux 2	0:1.7.3-15.amzn2.0.16 fixed
Amazon Linux 2023	0:1.17.1-1.amzn2023.0.14 fixed

unbound-libs

Amazon Linux 2	0:1.7.3-15.amzn2.0.16 fixed
Amazon Linux 2023	0:1.17.1-1.amzn2023.0.14 fixed

unbound-libs-debuginfo

Amazon Linux 2023

0:1.17.1-1.amzn2023.0.14

fixed

unbound-utils

Amazon Linux 2023

0:1.17.1-1.amzn2023.0.14

fixed

unbound-utils-debuginfo

Amazon Linux 2023

0:1.17.1-1.amzn2023.0.14

fixed

Azure Linux Releases

Azure Package

Release

unbound

Azure Linux 3.0

0:1.26.1-1.azl3

fixed

Common Weakness Enumeration

CWE-122 - Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

References

https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81642.txt