Dnsmasq: dnsmasq: denial of service due to out-of-bounds write in dhcp bootreply processing
Published Apr 17, 2026
7.5
HIGHCVSS 3.1
EPSS 0.58%
Description
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 products
No data.
No data.
No data.
Red Hat Enterprise Linux 10
dnsmasq
Not affected
Red Hat Enterprise Linux 6
dnsmasq
Not affected
Red Hat Enterprise Linux 7
dnsmasq
Not affected
Red Hat Enterprise Linux 8
dnsmasq
Not affected
Red Hat Enterprise Linux 9
dnsmasq
Not affected
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-8
Not affected
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-9
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | dnsmasq | Not affected | n/a |
| Red Hat Enterprise Linux 6 | dnsmasq | Not affected | n/a |
| Red Hat Enterprise Linux 7 | dnsmasq | Not affected | n/a |
| Red Hat Enterprise Linux 8 | dnsmasq | Not affected | n/a |
| Red Hat Enterprise Linux 9 | dnsmasq | Not affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected | n/a |
No package ranges for this CVE.
Remediation
Vendor solution
To mitigate this issue, ensure that the `dnsmasq` service is not configured with the `--dhcp-split-relay` option. If this option is currently in use, remove it from the `dnsmasq` configuration. After modifying the configuration, the `dnsmasq` service must be restarted for the changes to take effect. This may temporarily interrupt DHCP and DNS services provided by `dnsmasq`.
Red Hat mitigation
To mitigate this issue, ensure that the `dnsmasq` service is not configured with the `--dhcp-split-relay` option. If this option is currently in use, remove it from the `dnsmasq` configuration. After modifying the configuration, the `dnsmasq` service must be restarted for the changes to take effect. This may temporarily interrupt DHCP and DNS services provided by `dnsmasq`.
References (4)
- https://access.redhat.com/security/cve/CVE-2026-6507 vdb-entryx_refsource_REDHATVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2459181 issue-trackingx_refsource_REDHATIssue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2026-6507
- https://www.cve.org/CVERecord?id=CVE-2026-6507
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2026-6507 | vdb-entryx_refsource_REDHATVendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2459181 | issue-trackingx_refsource_REDHATIssue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2026-6507 | ||
| https://www.cve.org/CVERecord?id=CVE-2026-6507 |
Change history (0)
No recorded changes yet.