CVE-2026-12725: A heap-based buffer overflow was found in dnsmasq

Q: How do I fix CVE-2026-12725?

openshift container platform: upgrade to newer than 4.22.1; enterprise linux: mitigate or apply the listed mitigation; dnsmasq: upgrade to 2.93. Exact commands for each OS are on this page.

Q: Is CVE-2026-12725 being exploited?

CVE-2026-12725 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-12725 affect?

CVE-2026-12725 affects openshift container platform, enterprise linux, dnsmasq. Severity is medium (CVSS 5.9). A 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 int

Q: How urgent is CVE-2026-12725?

Priority 42/100. Remotely exploitable, no login, no user action; On your watchlist

This month

MEDIUM 5.9REMOTEWATCHLISTUPGRADEMITIGATEUPGRADE

CVE-2026-12725 is a medium-severity flaw (CVSS 5.9) affecting openshift container platform, enterprise linux, dnsmasq. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A 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.

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 56%)
CISA exploited list	No
Weakness	CWE-122
Published	2026-06-22
Last modified	2026-08-31

Publisher (CNA): Red Hat, Inc. · Vendor: redhat · thekelleys

Last updated 2026-08-31 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-22 16:16 UTCPublished CVE record published
2026-08-31 22:17 UTCUpdated Record last modified

redhat openshift container platform UPGRADE

Affected: >= 4.0 and <= 4.22.1

Fixed in: newer than 4.22.1

Safe to downgrade to: a release before 4.0

1. Check installed version

apt-cache policy openshift-container-platform || rpm -q openshift-container-platform || openshift-container-platform --version

2. UPGRADE to newer than 4.22.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade openshift-container-platform

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openshift-container-platform

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 4.0 (Debian / Ubuntu)

apt-cache madison openshift-container-platform sudo apt install openshift-container-platform=<VERSION_BEFORE_4.0> sudo apt-mark hold openshift-container-platform

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list openshift-container-platform sudo dnf downgrade openshift-container-platform-<VERSION_BEFORE_4.0> sudo dnf versionlock add openshift-container-platform

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat enterprise linux MITIGATE

Affected: 8.0 · 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

thekelleys dnsmasq UPGRADE

Affected: < 2.93

Fixed in: 2.93

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy dnsmasq || rpm -q dnsmasq || dnsmasq --version

2. UPGRADE to 2.93 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade dnsmasq

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade dnsmasq

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-12725?

openshift container platform: upgrade to newer than 4.22.1; enterprise linux: mitigate or apply the listed mitigation; dnsmasq: upgrade to 2.93. Exact commands for each OS are on this page.

Is CVE-2026-12725 being exploited?

CVE-2026-12725 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-12725 affect?

CVE-2026-12725 affects openshift container platform, enterprise linux, dnsmasq. Severity is medium (CVSS 5.9). A 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 int

How urgent is CVE-2026-12725?

Priority 42/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Dnsmasq vulnerabilities · Red Hat OpenShift vulnerabilities

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References

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