DNSMASQ TCP Connection Flood causing DNS Service Denial
CVE-2026-93007 Published on October 29, 2026

Dnsmasq: dnsmasq: tcp/53 child-slot exhaustion starves dnssec validation
A flaw was found in dnsmasq. The TCP DNS service uses a small fixed pool of child processes and does not set a receive timeout on client connections. A remote attacker can open idle TCP connections to port 53 and occupy the entire pool, preventing new TCP DNS connections and DNSSEC validation that requires TCP fallback. UDP DNS resolution continues, and occupied slots are released after a fixed lifetime.

NVD

Vulnerability Analysis

CVE-2026-93007 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
LOW

Timeline

Reported to Red Hat.

Made public. 44 days later.

Weakness Type

What is a Resource Exhaustion Vulnerability?

The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

CVE-2026-93007 has been classified to as a Resource Exhaustion vulnerability or weakness.


Products Associated with CVE-2026-93007

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Red Hat Ceph Storage
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Openshift
 
Red Hat Openstack
 

Affected Versions

Red Hat Ceph Storage 9: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat OpenShift Container Platform 4: Red Hat OpenShift Container Platform 4: Red Hat OpenShift Container Platform 4: Red Hat OpenShift Container Platform 4: Red Hat OpenStack Platform 13 (Queens): Red Hat OpenStack Platform 18.0: