Vulnerability · Published Oct 29, 2026 · Assigned by redhat
CVE-2026-93008Dnsmasq: dnsmasq: out-of-bailiwick cache injection through cname chase in split-dns configurations
Medium 6.8
In plain English
A medium-severity insufficient verification of data authenticity 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 0.1% (higher than 4% of all known vulnerabilities).
Official description
A flaw was found in dnsmasq. When following a CNAME in a DNS response, the resolver can cache records for the CNAME target without checking that those records belong to the responding server's authorized zone. In split-DNS deployments that send some domains to a specific upstream, an attacker who controls that upstream can inject cache entries for unrelated names. Later clients may then receive attacker-chosen addresses for those names.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | dnsmasq | no fix listed | DEBIAN-CVE-2026-93008 |
| Debian:13 | dnsmasq | no fix listed | DEBIAN-CVE-2026-93008 |
| Debian:14 | dnsmasq | no fix listed | DEBIAN-CVE-2026-93008 |
| Ubuntu:22.04:LTS | dnsmasq | no fix listed | UBUNTU-CVE-2026-93008 |
| Ubuntu:24.04:LTS | dnsmasq | no fix listed | UBUNTU-CVE-2026-93008 |
| Ubuntu:26.04:LTS | dnsmasq | no fix listed | UBUNTU-CVE-2026-93008 |
| Ubuntu:26.10 | dnsmasq | no fix listed | UBUNTU-CVE-2026-93008 |
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-345 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
References
- https://access.redhat.com/security/cve/CVE-2026-93008 vdb-entry, x_refsource_REDHAT
- RHBZ#2536079 issue-tracking, x_refsource_REDHAT