CVE-2026-6507
Dnsmasq: dnsmasq: denial of service due to out-of-bounds write in dhcp bootreply processing
What happened?
A flaw was found in dnsmasq. A remote attacker could exploit an out-of-bounds write vulnerability by sending a specially crafted BOOTREPLY (Bootstrap Protocol Reply) packet to a dnsmasq server configured with the `--dhcp-split-relay` option. This can lead to memory corruption, causing the dnsmasq daemon to crash and resulting in a denial of service (DoS).
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| dnsmasq | affected: 2.92 to < 2.93 | See vendor advisory |
| dnsmasqRed Hat | Default status: unaffected | See vendor advisory |
| dnsmasqRed Hat | Default status: unaffected | See vendor advisory |
| dnsmasqRed Hat | Default status: unaffected | See vendor advisory |
| dnsmasqRed Hat | Default status: unaffected | See vendor advisory |
| dnsmasqRed Hat | Default status: unaffected | See vendor advisory |
| openshift/ose-rhel-coreos-8Red Hat | Default status: unaffected | See vendor advisory |
| openshift/ose-rhel-coreos-9Red Hat | Default status: unaffected | 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.