CVE-2026-12725

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

Published Jun 22, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Workaround

Mitigate this issue by updating to a version of dnsmasq that includes the upstream fix (commit 36d081e37477027fd721fea498f3760f529034ad), or by disabling query logging if DNSSEC validation must remain enabled. After changing the configuration, restart the dnsmasq service for the changes to take effect.

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8542-1 Dnsmasq vulnerabilities
History
Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:openshift:5
cpe:/o:redhat:rhel_els:6
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els
Type Values Removed Values Added
First Time appeared Dnsmasq
Dnsmasq dnsmasq
Redhat openshift Container Platform
Vendors & Products Dnsmasq
Dnsmasq dnsmasq
Redhat openshift Container Platform
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Dnsmasq: dnsmasq: heap buffer overflow in log_query() when logging unsupported ds/dnskey replies
First Time appeared Redhat
Redhat enterprise Linux
Redhat openshift
Weaknesses CWE-122
CPEs cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat openshift
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 5, 2026, 5:03 PM
Reserved
Jun 19, 2026, 2:44 PM
Status
Analyzed
Published
Jun 22, 2026, 4:16 PM
Modified
Nov 5, 2026, 5:18 PM