Vulnerability · Published Oct 29, 2026 · Assigned by redhat
CVE-2026-93007Dnsmasq: dnsmasq: tcp/53 child-slot exhaustion starves dnssec validation
Medium 5.3
In plain English
A medium-severity uncontrolled resource consumption in Red Hat Ceph Storage 9 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities).
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | dnsmasq | no fix listed | DEBIAN-CVE-2026-93007 |
| Debian:13 | dnsmasq | no fix listed | DEBIAN-CVE-2026-93007 |
| Debian:14 | dnsmasq | no fix listed | DEBIAN-CVE-2026-93007 |
| Ubuntu:22.04:LTS | dnsmasq | no fix listed | UBUNTU-CVE-2026-93007 |
| Ubuntu:24.04:LTS | dnsmasq | no fix listed | UBUNTU-CVE-2026-93007 |
| Ubuntu:26.04:LTS | dnsmasq | no fix listed | UBUNTU-CVE-2026-93007 |
| Ubuntu:26.10 | dnsmasq | no fix listed | UBUNTU-CVE-2026-93007 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Ceph Storage 9 | see references |
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
| Red Hat | Red Hat OpenShift Container Platform 5 | see references |
| Red Hat | Red Hat OpenShift Container Platform 5 | see references |
| Red Hat | Red Hat OpenStack Platform 13 (Queens) | see references |
| Red Hat | Red Hat OpenStack Platform 18.0 | see references |
Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
- https://access.redhat.com/security/cve/CVE-2026-93007 vdb-entry, x_refsource_REDHAT
- RHBZ#2536076 issue-tracking, x_refsource_REDHAT