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.

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Fixes

Solution

No solution given by the vendor.


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.

History

Thu, 29 Oct 2026 12:45:00 +0000

Type Values Removed Values Added
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.
Title Dnsmasq: dnsmasq: out-of-bailiwick cache injection through cname chase in split-dns configurations
First Time appeared Redhat
Redhat ceph Storage
Redhat enterprise Linux
Redhat openshift
Redhat openstack
Weaknesses CWE-345
CPEs cpe:/a:redhat:ceph_storage:9
cpe:/a:redhat:openshift:4
cpe:/a:redhat:openstack:13
cpe:/a:redhat:openstack:18.0
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat ceph Storage
Redhat enterprise Linux
Redhat openshift
Redhat openstack
References
Metrics cvssV3_1

{'score': 6.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-10-29T12:33:22.941Z

Reserved: 2026-09-17T14:35:34.562Z

Link: CVE-2026-93008

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-29T13:17:16.053

Modified: 2026-10-29T13:17:16.167

Link: CVE-2026-93008

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses