Description
An out-of-bounds read vulnerability exists in dnsmasq's find_soa() function in src/rfc1035.c. When parsing NS section records, extract_name() is called with extrabytes=0, failing to validate that 10 additional bytes exist for fixed-length DNS record fields. A remote attacker controlling a DNS zone can exploit this via a crafted NXDOMAIN response to cause a 10-byte heap out-of-bounds read, potentially accessing stale data from prior transactions.
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 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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 |
| SLE Micro 6.1 | dnsmasq | 2.93-slfo.1.1_2.1 | SUSE-SU-2026:22668-1 |
| 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 | 2.93-2.1 | openSUSE-SU-2026:11172-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | dnsmasq | 2.93-1 | — |
Advisories 7
- SUSE-SU-2026:22706-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 23, 2026
- WID-SEC-2026-2042 dnsmasq: Schwachstelle ermöglicht Offenlegung von Informationen BSI CERT-Bund (WID) · Jul 22, 2026
- SUSE-SU-2026:22668-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Jul 21, 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
- openSUSE-SU-2026:11172-1 dnsmasq-2.93-2.1 on GA media SUSE / openSUSE Security Updates · Jul 3, 2026
References
- https://access.redhat.com/security/cve/CVE-2026-12969 vdb-entry
- RHBZ#2491663 issue-tracking