CVE-2026-12725 Dnsmasq: dnsmasq: heap buffer overflow in log_query() when logging unsupported ds/dnskey replies

What is CVE-2026-12725?

CVE-2026-12725 is a medium-severity memory corruption vulnerability in Redhat Enterprise Linux, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-122

Which versions are affected by CVE-2026-12725?

It affects 3 products.

Products include Redhat Enterprise Linux, Redhat Openshift Container Platform, Thekelleys Dnsmasq.

How do I fix CVE-2026-12725?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-12725 being exploited?

There is no known exploitation of CVE-2026-12725 in the wild and no public exploit code.

Other vulnerabilities in Redhat Enterprise Linux

• CVE-2018-14667 Red Hat JBoss RichFaces Framework Expression Language Injection Exploited Critical 9.8
• CVE-2021-20325 Missing fixes for CVE-2021-40438 and CVE-2021-26691 in the versions of httpd, as shipped in Red Hat Enterprise Linux 8.5.0, causes a securit Critical 9.8
• CVE-2018-25011 Memory corruption in libwebp Critical 9.8
• CVE-2018-25014 Other in libwebp Critical 9.8
• CVE-2014-3585 Supply chain in redhat-upgrade-tool Critical 9.8

All Redhat Enterprise Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-91167, BELL-CVE-2026-12725, CLSA-2026-1784640629, CLSA-2026-1784645899, DEBIAN-CVE-2026-12725, ECHO-6187-52bc-032f and 5 more.