Description
An issue was discovered in Dnsmasq before 2.90. The default maximum EDNS.0 UDP packet size was set to 4096 but should be 1232 because of DNS Flag Day 2020.
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 | 2.90-1 | — |
| Debian 13 | dnsmasq | 2.90-1 | — |
| Debian 12 | dnsmasq | 2.90-4~deb12u1 | — |
| Debian 11 | dnsmasq | 2.85-1+deb11u1 | DLA-3974-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | dnsmasq | 2.86-1.1ubuntu0.3 | USN-6657-1, USN-6034-1 |
| Ubuntu 20.04 LTS | dnsmasq | 2.80-1.1ubuntu1.7 | USN-6657-1, USN-6034-1 |
| Ubuntu 18.04 LTS | dnsmasq | 2.79-1ubuntu0.7 | USN-6034-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | dnsmasq | 2.90-0ubuntu0.18.04.1+esm1 | USN-6657-2 |
| Ubuntu Pro 16.04 LTS | dnsmasq | 2.79-1ubuntu0.16.04.1+esm2 | USN-6657-2, USN-6034-1 |
| Ubuntu Pro 14.04 LTS | dnsmasq | 2.68-1ubuntu0.2+esm2 | USN-6034-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | dnsmasq +1 | 2.85-14.el9 | RHSA-2023:6524 |
| RHEL 8 | dnsmasq +1 | 2.79-31.el8 | RHSA-2023:7046 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9.2 EUS | dnsmasq +1 | 2.85-6.el9_2.4 | RHSA-2024:4052 |
| RHEL 8.8 EUS | dnsmasq +1 | 2.79-26.el8_8.4 | RHSA-2024:1544 |
| RHEL 8.6 EUS | dnsmasq +1 | 2.79-21.el8_6.5 | RHSA-2024:1545 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | dnsmasq +1 | 2.85-14.el9 | ALSA-2023:6524 |
| AlmaLinux 8 | dnsmasq +1 | 2.79-31.el8 | ALSA-2023:7046 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLES 15 SP5 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLES 15 SP4 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLES 12 SP5 | dnsmasq | 2.78-18.21.1 | SUSE-SU-2023:2123-1 |
Show 19 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP5 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLES for SAP 15 SP4 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLES for SAP 12 SP5 | dnsmasq | 2.78-18.21.1 | SUSE-SU-2023:2123-1 |
| SLE Real Time 15 SP3 | dnsmasq | 2.86-150100.7.23.1 | SUSE-SU-2023:1930-1 |
| SLE Micro 6.0 | dnsmasq | 2.90-1.1 | SUSE-SU-2025:20118-1 |
| SLE Micro 5.5 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLE Micro 5.4 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLE Micro 5.3 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLE Micro 5.2 | dnsmasq | 2.86-150100.7.23.1 | SUSE-SU-2023:1930-1 |
| SLE Micro 5.1 | dnsmasq | 2.86-150100.7.23.1 | SUSE-SU-2023:1930-1 |
| SLE HPC 15 SP5 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SLE HPC 15 SP4 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SUSE OpenStack Cloud Crowbar 9 | dnsmasq | 2.78-18.21.1 | SUSE-SU-2023:2123-1 |
| SUSE OpenStack Cloud Crowbar 8 | dnsmasq | 2.78-18.21.1 | SUSE-SU-2023:2123-1 |
| SUSE OpenStack Cloud 9 | dnsmasq | 2.78-18.21.1 | SUSE-SU-2023:2123-1 |
| SUSE OpenStack Cloud 8 | dnsmasq | 2.78-18.21.1 | SUSE-SU-2023:2123-1 |
| SUSE Manager Server 4.3 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SUSE Manager Proxy 4.3 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
| SUSE HPE Helion OpenStack 8 | dnsmasq | 2.78-18.21.1 | SUSE-SU-2023:2123-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dnsmasq | 2.89-3.1 | openSUSE-SU-2024:12887-1 |
| openSUSE Leap 15.6 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap Micro 5.5 | dnsmasq | 2.90-150400.16.3.1 | SUSE-SU-2025:0071-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | dnsmasq | 2.89-r3 | — |
| Alpine v3.23 | dnsmasq | 2.89-r3 | — |
| Alpine v3.22 | dnsmasq | 2.89-r3 | — |
| Alpine v3.21 | dnsmasq | 2.89-r3 | — |
| Alpine v3.20 | dnsmasq | 2.89-r3 | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | dnsmasq | 2.89-r3 | — |
| Alpine v3.18 | dnsmasq | 2.89-r3 | — |
| Alpine v3.17 | dnsmasq | 2.87-r2 | — |
| Alpine v3.16 | dnsmasq | 2.86-r4 | — |
| Alpine v3.15 | dnsmasq | 2.86-r2 | — |
| Alpine v3.14 | dnsmasq | 2.86-r3 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | dnsmasq +1 | 2.86-10.amzn2023.0.3 | ALAS2023-2023-192 |
| Amazon Linux 2 | dnsmasq +1 | 2.76-16.amzn2.1.4 | ALAS2-2023-2069 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | dnsmasq | 2.89-2 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | dnsmasq +1 | 2.85-14.el9 | ELSA-2023-6524 |
| Oracle Linux 8 | dnsmasq +1 | 2.79-31.el8 | ELSA-2023-7046 |
Advisories 27
- ALSA-2023:6524 Moderate: dnsmasq security and bug fix update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2023:7046 Moderate: dnsmasq security and bug fix update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2023-2917 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 30, 2026
- USN-6034-1 dnsmasq vulnerability Ubuntu Security Notices (USN) · Jun 29, 2026
- USN-6657-2 dnsmasq vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- RHSA-2023:7046 Red Hat Security Advisory: dnsmasq security and bug fix update Red Hat Security Advisories (RHSA) · May 1, 2026
- RHSA-2023:6524 Red Hat Security Advisory: dnsmasq security and bug fix update Red Hat Security Advisories (RHSA) · May 1, 2026
- RHSA-2024:4052 Red Hat Security Advisory: dnsmasq security update Red Hat Security Advisories (RHSA) · May 1, 2026
- RHSA-2024:1545 Red Hat Security Advisory: dnsmasq security update Red Hat Security Advisories (RHSA) · May 1, 2026
- RHSA-2024:1544 Red Hat Security Advisory: dnsmasq security and bug fix update Red Hat Security Advisories (RHSA) · May 1, 2026
- USN-6657-1 dnsmasq vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- SUSE-SU-2025:20118-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Mar 23, 2026
- DLA-3974-1 dnsmasq - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2025:0071-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:1930-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:12887-1 dnsmasq-2.89-3.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:2123-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-0668 dnsmasq: Schwachstelle ermöglicht nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 6, 2025
- ICSA-24-319-06 Siemens SCALANCE M-800 Family CISA ICS & IT advisories · May 6, 2025
- NCSC-2024-0433 Kwetsbaarheden verholpen in Siemens producten NCSC-NL (Netherlands) · Nov 12, 2024
- SSA-354112 SSA-354112: Multiple Vulnerabilities in SCALANCE M-800 Family Before V8.2 Siemens ProductCERT · Nov 12, 2024
- ICSA-24-046-11 Siemens SCALANCE XCM-/XRM-300 CISA ICS & IT advisories · Feb 13, 2024
- SSA-806742 SSA-806742: Multiple Vulnerabilities in SCALANCE XCM-/XRM-300 before V2.4 Siemens ProductCERT · Feb 13, 2024
- ELSA-2023-7046 Moderate: dnsmasq security and bug fix update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 17, 2023
- ELSA-2023-6524 Moderate: dnsmasq security and bug fix update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 11, 2023
- ALAS2-2023-2069 Moderate: dnsmasq security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jun 7, 2023
- ALAS2023-2023-192 Moderate: dnsmasq security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 7, 2023
References
- https://thekelleys.org.uk/dnsmasq/doc.html
- https://thekelleys.org.uk/gitweb/?p=dnsmasq.git%3Ba=commit%3Bh=eb92fb32b746f2104b0f370b5b295bb8dd4bd5e5
- https://thekelleys.org.uk/gitweb/?p=dnsmasq.git%3Ba=blob%3Bf=CHANGELOG
- https://capec.mitre.org/data/definitions/495.html
- FEDORA-2023-828bf01834 vendor-advisory
- FEDORA-2023-eeca11a4df vendor-advisory