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Fencer Vulns
medium 5.3

CVE-2026-93007 json

Dnsmasq: dnsmasq: tcp/53 child-slot exhaustion starves dnssec validation

published 2026-10-29 10 d ago modified 2026-11-06 3 d ago also EUVD-2026-112790

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

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.

Patch / fix

  • dnsmasq openSUSE Tumbleweed 2.93-3.1

opensuse advisories openSUSE-SU-2026:12415-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-93007 updated cvss 5.3

dnsmasq: dnsmasq: TCP/53 child-slot exhaustion starves DNSSEC validation

  • Red Hat Ceph Storage 9 rhceph/alloy-rhel10 Red Hat Enterprise Linux 6 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 7 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 8 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 9 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 10 dnsmasq
    +4 more products
    Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9, openshift4/ose-baremetal-runtimecfg-rhel8, openshift4/ose-baremetal-runtimecfg-rhel9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9, openshift5/ose-baremetal-runtimecfg-rhel9 Red Hat OpenStack Platform 13 (Queens) dnsmasq-utils Red Hat OpenStack Platform 18.0 rhoso-operators/infra-rhel9-operator
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
10 d ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

  • Red Hat Red Hat Ceph Storage 9
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4
  • Red Hat Red Hat OpenShift Container Platform 5
  • Red Hat Red Hat OpenStack Platform 13 (Queens)
  • Red Hat Red Hat OpenStack Platform 18.0

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.