What’s Vulnerable › Vulnerabilities

CVE-2026-93007: Dnsmasq: dnsmasq: tcp/53 child-slot exhaustion starves dnssec validation

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-29 · updated 2026-10-30
• Weakness: CWE-400

Description

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.

Affected products

• Red Hat OpenShift Container Platform 4.18: all versions
• Red Hat Ceph Storage 9: all versions
• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 6: all versions
• Red Hat Enterprise Linux 7: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions
• Red Hat OpenShift Container Platform 5: all versions
• Red Hat OpenStack Platform 13 (Queens): all versions
• Red Hat OpenStack Platform 18.0: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-93007
• https://bugzilla.redhat.com/show_bug.cgi?id=2536076

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