CVE-2026-42944
highpriority · track · 30EPSS 0.008 · 58 %ileDEEURUUSEPSS · scored 2026-10-26
NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses' (default)) need to be enabled for the vulnerability to be exploited. An adversary who can query Unbound can exploit the vulnerability by attaching multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options to the query. A flaw in the size calculation of the EDNS field truncates the correct value which allows the encoder to overflow the available space when writing. Those two combined lead to a heap overflow write of Unbound controlled data and eventually a crash. Unbound 1.25.1 contains a patch with a fix to de-duplicate the EDNS options and a fix to prevent truncation of the EDNS field size calculation.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (41)
Products and version ranges known to be affected.
- Red Hat OpenShift Container Platformall versionscert_bundDEcpe:/a:redhat:openshift:container_platform
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-1599Unbound: Mehrere SchwachstellenDeutsch2026-05-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Unbound ausnutzen, um einen Denial of Service Zustand herbeizuführen, um möglicherweise Code auszuführen und um nicht näher spezifizierte Auswirkungen zu verursachen.
- WID-SEC-W-2026-2455Oracle Solaris Drittanbieterkomponenten: Mehrere SchwachstellenDeutsch2026-07-21csaf · cert_bundDE
Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in verschiedenen Komponenten von Drittanbietern in Oracle Solaris ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (13)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2026-42944cnnvd
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42944cnnvd
- https://nlnetlabs.nl/downloads/unbound/Patchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-42944cnnvd
- https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-42944.txtenisa_euvd
- https://access.redhat.com/errata/RHSA-2026:19752nvd
- https://access.redhat.com/errata/RHSA-2026:23231nvd
- https://access.redhat.com/errata/RHSA-2026:24365nvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan