Public vulnerability disclosure

CVE-2026-93006

Dnsmasq: dnsmasq: tftp prefetch cache keyed on stale heap pointer serves wrong file content

publishedCWE-672

A flaw was found in dnsmasq. The TFTP server can serve the wrong file contents because a recently used transfer cache is not invalidated when a transfer finishes. An attacker on the local network who can request a TFTP file may cause a later client to receive previously cached data instead of the requested file. In PXE network-boot environments this can substitute attacker-chosen boot content for a victim machine.

Technical severity6.8 mediumCVSS 3.1 · CNA: redhat
Published2026-10-29Source updated 2026-11-02
Collected2026-11-022 attributed sources

Fixes and workarounds

Workaround

The following measures reduce risk: 1. If TFTP is not required, do not enable it. Remove --enable-tftp from the dnsmasq configuration. 2. If TFTP is required, restrict it with --tftp-interface=<interface> and avoid running TFTP-only instances that serve untrusted clients on the same network. 3. Compile without TFTP support using COPTS=-DNO_TFTP if TFTP is not needed.

Source: CNA: redhat

Affected products and versions

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
Red Hat Ceph Storage 9
Red Hat
rhceph/alloy-rhel10
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat Enterprise Linux 10
Red Hat
dnsmasq
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat Enterprise Linux 6
Red Hat
dnsmasq
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat Enterprise Linux 7
Red Hat
dnsmasq
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat Enterprise Linux 8
Red Hat
dnsmasq
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat Enterprise Linux 9
Red Hat
dnsmasq
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift4/ose-baremetal-runtimecfg-rhel8
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift4/ose-baremetal-runtimecfg-rhel9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift/ose-rhel-coreos-8
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenShift Container Platform 5
Red Hat
openshift5/ose-baremetal-runtimecfg-rhel9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenShift Container Platform 5
Red Hat
openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenStack Platform 13 (Queens)
Red Hat
dnsmasq
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat
Red Hat OpenStack Platform 18.0
Red Hat
rhoso-operators/infra-rhel9-operator
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: affected
CNA: redhat

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / scoreVectorAuthority
3.1 / 6.8
medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCNA: redhat

Exploit evidence

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

References

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