CVE-2026-93011
Dnsmasq: dnsmasq: heap out-of-bounds write in dnssec validator via to_wire/from_wire transforms
What happened?
A flaw was found in dnsmasq. After a reduction of internal domain-name buffer sizes, the DNSSEC validator can write a few bytes past a name buffer when converting names to and from DNS wire format. An attacker who can cause the server to validate a crafted DNSSEC response may overwrite a small amount of adjacent heap metadata. DNSSEC support is not compiled in by default and must also be enabled at runtime.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| rhceph/alloy-rhel10Red Hat | Default status: affected | See vendor advisory |
| dnsmasqRed Hat | Default status: affected | See vendor advisory |
| dnsmasqRed Hat | Default status: affected | See vendor advisory |
| dnsmasqRed Hat | Default status: affected | See vendor advisory |
| dnsmasqRed Hat | Default status: affected | See vendor advisory |
| dnsmasqRed Hat | Default status: affected | See vendor advisory |
| openshift4/ose-baremetal-runtimecfg-rhel8Red Hat | Default status: affected | See vendor advisory |
| openshift4/ose-baremetal-runtimecfg-rhel9Red Hat | Default status: affected | See vendor advisory |
| openshift/ose-rhel-coreos-8Red Hat | Default status: affected | See vendor advisory |
| openshift/ose-rhel-coreos-9Red Hat | Default status: affected | See vendor advisory |
| openshift5/ose-baremetal-runtimecfg-rhel9Red Hat | Default status: affected | See vendor advisory |
| openshift/ose-rhel-coreos-9Red Hat | Default status: affected | See vendor advisory |
| dnsmasqRed Hat | Default status: affected | See vendor advisory |
| rhoso-operators/infra-rhel9-operatorRed Hat | Default status: affected | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.