Description
A heap-based buffer overflow was found in dnsmasq. When DNSSEC validation and
query logging are both enabled, logging of DS or DNSKEY replies containing
unsupported algorithm or digest types can cause dnsmasq to write past the end
of an internal logging buffer. A remote attacker able to supply such a DNS
response may crash the dnsmasq process, resulting in denial of service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 6 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | dnsmasq | 2.93-1 | — |
| Debian 13 | dnsmasq | 2.91-1+deb13u2 | — |
| Debian 12 | dnsmasq | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | dnsmasq | 2.92-1ubuntu0.4 | USN-8542-1 |
| Ubuntu 25.10 | dnsmasq | No fix yet | — |
| Ubuntu 24.04 LTS | dnsmasq | 2.90-2ubuntu0.4 | USN-8542-1 |
| Ubuntu 22.04 LTS | dnsmasq | 2.90-0ubuntu0.22.04.4 | USN-8542-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | dnsmasq | 2.90-0ubuntu0.20.04.1+esm3 | USN-8542-1 |
| Ubuntu Pro 18.04 LTS | dnsmasq | 2.90-0ubuntu0.18.04.1+esm4 | USN-8542-1 |
| Ubuntu Pro 16.04 LTS | dnsmasq | 2.90-0ubuntu0.16.04.1+esm4 | USN-8542-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLES 15 SP6 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLES 15 SP5 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLES 15 SP4 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLES 12 SP5 | dnsmasq | 2.93-18.32.1 | SUSE-SU-2026:2974-1 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | dnsmasq | 2.93-160000.1.1 | SUSE-SU-2026:22496-1 |
| SLES for SAP 15 SP6 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLES for SAP 15 SP5 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLES for SAP 15 SP4 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLES 16.0 | dnsmasq | 2.93-160000.1.1 | SUSE-SU-2026:22496-1 |
| SLE Micro 6.1 | dnsmasq | 2.93-slfo.1.1_1.1 | SUSE-SU-2026:22454-1 |
| SLE Micro 6.0 | dnsmasq | 2.93-1.1 | SUSE-SU-2026:22706-1 |
| SLE Micro 5.5 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLE Micro 5.4 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLE Micro 5.3 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLE HPC 15 SP5 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
| SLE HPC 15 SP4 | dnsmasq | 2.93-150400.16.17.1 | SUSE-SU-2026:3028-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dnsmasq | 2.93-1.1 | openSUSE-SU-2026:11116-1 |
| openSUSE Leap 16.0 | dnsmasq | 2.93-160000.1.1 | openSUSE-SU-2026:21192-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | dnsmasq | 2.93-1 | — |
Advisories 9
- SUSE-SU-2026:22706-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 23, 2026
- WID-SEC-2026-2036 dnsmasq: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Jul 22, 2026
- SUSE-SU-2026:3028-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 16, 2026
- SUSE-SU-2026:2974-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 15, 2026
- USN-8542-1 dnsmasq vulnerabilities Ubuntu Security Notices (USN) · Jul 15, 2026
- SUSE-SU-2026:22496-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 7, 2026
- SUSE-SU-2026:22454-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 4, 2026
- openSUSE-SU-2026:21192-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 3, 2026
- openSUSE-SU-2026:11116-1 dnsmasq-2.93-1.1 on GA media SUSE / openSUSE Security Updates · Jun 26, 2026
References
- https://access.redhat.com/security/cve/CVE-2026-12725 vdb-entry
- RHBZ#2490763 issue-tracking