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Fencer Intel
high 7.5

CVE-2026-44690 json

Cross-zone wildcard cache poisoning via RRSIG.labels manipulation

published 3mo ago modified 16d ago also EUVD-2026-47669

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, insufficient validation of the RRSIG.Labels field combined with premature cache writes during RFC 8198 aggressive NSEC processing leads to cache poisoning that permits a malicious actor controlling a single delegated zone to poison arbitrary sibling zones under NSEC-signed parent domains. A malicious actor with one registered domain under an NSEC-signed TLD can serve malicious insecure DNS responses for unrelated sibling domains (sharing the same parent zone). Arbitrary delegations that do not exist under the parent domain and are covered by the parent's NSEC chain can be brought into insecure existence by fraudulent wildcard DS records (less labels than expected, unknown algorithm) from the malicious sibling domain. This allows the malicious actor to inject insecure wildcard records for those delegations.

Patch / fix

  • NLnet Labs Unbound 1.25.2
  • unbound Debian 13 1.26.1-0+deb13u1
  • unbound Debian 14 1.25.2-1

debian advisories DEBIAN-CVE-2026-44690

  • unbound Ubuntu 22.04 LTS 1.13.1-1ubuntu5.17
  • unbound Ubuntu 24.04 LTS 1.19.2-1ubuntu3.12
  • unbound Ubuntu 26.04 LTS 1.24.2-1ubuntu2.4
  • unbound Ubuntu Pro 20.04 LTS 1.9.4-2ubuntu1.11+esm3

ubuntu advisories UBUNTU-CVE-2026-44690

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • unbound RHEL 10.2 1.24.2-7.el10_2.4
  • unbound-libs RHEL 10.2 1.24.2-7.el10_2.4
  • unbound-utils RHEL 10.2 1.24.2-7.el10_2.4
  • unbound-anchor RHEL 10.2 1.24.2-7.el10_2.4
  • unbound-dracut RHEL 10.2 1.24.2-7.el10_2.4
  • python3-unbound RHEL 10.2 1.24.2-7.el10_2.4
  • unbound RHEL 9 1.24.2-3.el9_8.4
  • unbound-libs RHEL 9 1.24.2-3.el9_8.4

red hat advisories RHSA-2026:55892RHSA-2026:55841RHSA-2026:55784RHSA-2026:43588

  • unbound SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Package Hub 15 SP7 +1 more 1.25.2-150600.23.19.1
  • unbound SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +6 more 1.25.2-150100.10.28.1
  • unbound Linux Micro 6.0 1.25.2-1.1
  • unbound Linux Micro 6.1 1.25.2-slfo.1.1_1.1
  • unbound SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 1.25.2-160000.1.1

suse advisories SUSE-SU-2026:3885-1SUSE-SU-2026:3884-1SUSE-SU-2026:23360-1SUSE-SU-2026:23349-1SUSE-SU-2026:23050-1SUSE-SU-2026:23215-1

  • unbound openSUSE Leap 16.0 1.25.2-160000.1.1
  • unbound openSUSE Tumbleweed 1.25.2-1.1

opensuse advisories openSUSE-SU-2026:21550-1openSUSE-SU-2026:11380-1

  • unbound AlmaLinux 8 1.16.2-5.14.el8_10
  • unbound-libs AlmaLinux 8 1.16.2-5.14.el8_10
  • python3-unbound AlmaLinux 8 1.16.2-5.14.el8_10
  • unbound AlmaLinux 9 1.24.2-3.el9_8.4
  • unbound-libs AlmaLinux 9 1.24.2-3.el9_8.4
  • unbound-dracut AlmaLinux 9 1.24.2-3.el9_8.4
  • python3-unbound AlmaLinux 9 1.24.2-3.el9_8.4
  • unbound AlmaLinux 10 1.24.2-7.el10_2.4

almalinux advisories ALSA-2026:55784ALSA-2026:55841ALSA-2026:55892

  • unbound Rocky Linux 10 1.24.2-7.el10_2.4
  • unbound Rocky Linux 9 1.24.2-3.el9_8.4
  • unbound Rocky Linux 8 1.16.2-5.14.el8_10

rocky linux advisories RLSA-2026:55892RLSA-2026:55841RLSA-2026:55784

  • unbound Alpine 3.24, Alpine 3.23, Alpine 3.22 1.25.2-r0

alpine advisories ALPINE-CVE-2026-44690

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • unbound Azure Linux 3.0 1.25.2-1

azure linux advisories AZL-92931

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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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-2026-44690 updated cvss 8.6

unbound: Unbound: Cache poisoning via insufficient RRSIG.Labels validation and premature cache writes

  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 8) unbound 1.16.2-5.14.el8_10, unbound-libs 1.16.2-5.14.el8_10, python3-unbound 1.16.2-5.14.el8_10
    fixed: vendor fix RHSA-2026:55784
  • Red Hat Enterprise Linux AppStream (v. 9) unbound 1.24.2-3.el9_8.4, unbound-libs 1.24.2-3.el9_8.4, unbound-dracut 1.24.2-3.el9_8.4, python3-unbound 1.24.2-3.el9_8.4
    fixed: vendor fix RHSA-2026:55841
  • Red Hat Enterprise Linux AppStream (v. 10) unbound 1.24.2-7.el10_2.4, unbound-libs 1.24.2-7.el10_2.4, unbound-utils 1.24.2-7.el10_2.4, unbound-anchor 1.24.2-7.el10_2.4, unbound-dracut 1.24.2-7.el10_2.4, python3-unbound 1.24.2-7.el10_2.4
    fixed: vendor fix RHSA-2026:55892
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) unbound-devel 1.24.2-3.el9_8.4, unbound-debuginfo 1.24.2-3.el9_8.4, unbound-debugsource 1.24.2-3.el9_8.4, unbound-libs-debuginfo 1.24.2-3.el9_8.4, python3-unbound-debuginfo 1.24.2-3.el9_8.4
    fixed: vendor fix RHSA-2026:55841
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) unbound-devel 1.24.2-7.el10_2.4, unbound-debuginfo 1.24.2-7.el10_2.4, unbound-debugsource 1.24.2-7.el10_2.4, unbound-libs-debuginfo 1.24.2-7.el10_2.4, unbound-utils-debuginfo 1.24.2-7.el10_2.4, unbound-anchor-debuginfo 1.24.2-7.el10_2.4, +1 more
    fixed: vendor fix RHSA-2026:55892
  • Red Hat Hardened Images unbound 1.25.2-0.1.hum1, unbound-libs 1.25.2-0.1.hum1, unbound-munin 1.25.2-0.1.hum1, unbound-utils 1.25.2-0.1.hum1, unbound-anchor 1.25.2-0.1.hum1, unbound-dracut 1.25.2-0.1.hum1, +1 more
    fixed: vendor fix RHSA-2026:43588
  • Red Hat OpenShift Container Platform 4.22 rhcos 4.22.9.8.202608251819
    fixed: vendor fix RHSA-2026:60440
show 1 more
  • Red Hat Enterprise Linux 6 unbound, unbound-libs, unbound-python Red Hat Enterprise Linux 7 unbound, unbound-libs, unbound-python
    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

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

  • NLnet Labs Unbound

Classification

Weakness
  • CWE-345 Insufficient Verification of Data Authenticity

References

Sources

Fencer Intel 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.