# CVE-2026-93008: Dnsmasq: dnsmasq: out-of-bailiwick cache injection through cname chase in split-dns configurations

Status: published. Published: 2026-10-29. Updated: 2026-11-05.

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.

## Remediation

- workaround: The following measures reduce risk:

1. Do not point server=/domain/ at untrusted or attacker-reachable DNS servers.
2. Restrict dnsmasq to communicate only with trusted upstream resolvers at the firewall.
3. For local=/domain/ zones, define all names that should be served locally.
4. Do not rely on --dnssec to mitigate this for unsigned zones. Insecure records are still cached. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Ceph Storage 9 (rhceph/alloy-rhel10): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (dnsmasq): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (dnsmasq): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (dnsmasq): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (dnsmasq): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (dnsmasq): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift4/ose-baremetal-runtimecfg-rhel8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift4/ose-baremetal-runtimecfg-rhel9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift5/ose-baremetal-runtimecfg-rhel9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenStack Platform 13 (Queens) (dnsmasq): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenStack Platform 18.0 (rhoso-operators/infra-rhel9-operator): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N; source: CNA: redhat

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.15% as of 2026-11-04; percentile 4.17%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-345

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2026-93008 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2536079 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-93008 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2536079 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-93008; retrieved 2026-11-05; source updated 2026-11-05

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93008; retrieved 2026-11-03; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-93008; retrieved 2026-11-05; source updated Not reported

Revision: 8a79f2901b97d8a0d6cbd9041ffd95e04db0684416f6911207d7f878afa72a39

Canonical: https://y2.dev/cve/CVE-2026-93008

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