Openshift Container PlatformApplication · Redhat
CVE-2026-12725
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA heap-based buffer overflow was found in dnsmasq. When DNSSEC validation and query logging are both enabled, logging of DS or DNSKEY replies containing unsupported algorithm or digest types can cause dnsmasq to write past the end of an internal logging buffer. A remote attacker able to supply such a DNS response may crash the dnsmasq process, resulting in denial of service.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceHeap-based buffer overflow in dnsmasq occurring when both DNSSEC validation and query logging are enabled. When dnsmasq logs DS or DNSKEY replies containing unsupported algorithm or digest types, it writes past the end of an internal logging buffer. A remote attacker able to supply malicious DNS responses can trigger this overflow and crash dnsmasq, causing denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Openshift Container PlatformApplication
>= 4.0, <= 4.22.1
Enterprise LinuxOperating system
= 8.0= 9.0= 10.0< 2.93CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify dnsmasq versionRun 'dnsmasq --version' or 'rpm -q dnsmasq' to obtain the installed version numberAffected if Version is lower than 2.93 (for upstream) or falls within RHEL 8.0, 9.0, 10.0 or OCP 4.0-4.22.1
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Locate dnsmasq configuration filesInspect /etc/dnsmasq.conf and any files in /etc/dnsmasq.d/ directory for active configuration directivesAffected if Configuration files exist and dnsmasq is actively running
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Verify if DNSSEC validation is enabledSearch configuration for 'dnssec', 'dnssec-check-unsigned', or 'dnssec-trust-anchors' directives - these indicate DNSSEC is activeAffected if Any dnssec-related directives are present and uncommented in the active configuration
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Verify if query logging is enabledSearch configuration for 'log-queries', 'log-dhcp', or other 'log-*' directives that enable query loggingAffected if Any query or request logging directives are present and uncommented in the active configuration
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Confirm both features are simultaneously enabledReview all active configuration to confirm BOTH DNSSEC validation (dnssec directives) AND query logging (log-queries/log-dhcp) are enabled at the same timeAffected if Both DNSSEC and query logging are enabled together - this is the required condition for the vulnerability to be exploitable
You are affected if dnsmasq is running with a vulnerable version AND has both DNSSEC validation and query logging enabled simultaneously, allowing a remote attacker supplying malicious DNS responses to overflow the logging buffer and crash the service.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2.93
Disable either DNSSEC validation or query logging in dnsmasq configuration until a patch is available; alternatively, restrict who can send DNS responses to the server to reduce attack surface.
dnsmasq >= 2.93, RHEL 8.0+/9.0+/10.0+ with security updates, OpenShift Container Platform > 4.22.1
- 1. Identify all systems running dnsmasq with DNSSEC validation and query logging enabled
- 2. For RHEL/RHEL CoreOS systems: run 'dnf update dnsmasq' or 'yum update dnsmasq' to apply the latest security patches
- 3. For OpenShift Container Platform: update to a version newer than 4.22.1 (e.g., 4.23 or later) using the oc adm upgrade command
- 4. After updating, verify the dnsmasq version is 2.93 or later using 'dnsmasq --version'
- 5. Restart the dnsmasq service to load the updated version: 'systemctl restart dnsmasq' (or appropriate service restart for your environment)
- 6. Confirm DNSSEC validation and logging still function correctly after the update
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Openshift Container Platform
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-12725 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-12725 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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