Description
Memory leak in dnsmasq before 2.78, when the --add-mac, --add-cpe-id or --add-subnet option is specified, allows remote attackers to cause a denial of service (memory consumption) via vectors involving DNS response creation.
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 | 2.78-1 | — |
| Debian 13 | dnsmasq | 2.78-1 | — |
| Debian 12 | dnsmasq | 2.78-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | dnsmasq | 2.75-1ubuntu0.16.04.3 | USN-3430-1 |
| Ubuntu 14.04 LTS | dnsmasq | 2.68-1ubuntu0.2 | USN-3430-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | dnsmasq +1 | 2.76-2.el7_4.2 | RHSA-2017:2836 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SLES 12 SP2 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SLES 12 SP1 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SLES 12 | dnsmasq | 2.78-6.6.1 | SUSE-SU-2017:2616-1 |
| SLES 11 SP4 | dnsmasq | 2.78-0.17.5.1 | SUSE-SU-2017:2619-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP3 | dnsmasq | 2.78-0.16.5.1 | SUSE-SU-2017:2617-1 |
| SLES for SAP 12 SP3 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SLES for SAP 12 SP2 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SLES for SAP 12 SP1 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SLES for SAP 11 SP4 | dnsmasq | 2.78-0.17.5.1 | SUSE-SU-2017:2619-1 |
| SUSE OpenStack Cloud 7 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SUSE OpenStack Cloud 6 | dnsmasq | 2.78-18.3.1 | SUSE-SU-2017:2618-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | dnsmasq | 2.78-0.16.5.1 | SUSE-SU-2017:2617-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dnsmasq | 2.86-1.1 | openSUSE-SU-2024:10721-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | dnsmasq | 2.78-r0 | — |
| Alpine v3.23 | dnsmasq | 2.78-r0 | — |
| Alpine v3.22 | dnsmasq | 2.78-r0 | — |
| Alpine v3.21 | dnsmasq | 2.78-r0 | — |
| Alpine v3.20 | dnsmasq | 2.78-r0 | — |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | dnsmasq | 2.78-r0 | — |
| Alpine v3.18 | dnsmasq | 2.78-r0 | — |
| Alpine v3.17 | dnsmasq | 2.78-r0 | — |
| Alpine v3.16 | dnsmasq | 2.78-r0 | — |
| Alpine v3.15 | dnsmasq | 2.78-r0 | — |
| Alpine v3.14 | dnsmasq | 2.78-r0 | — |
| Alpine v3.13 | dnsmasq | 2.78-r0 | — |
| Alpine v3.12 | dnsmasq | 2.78-r0 | — |
| Alpine v3.11 | dnsmasq | 2.78-r0 | — |
| Alpine v3.10 | dnsmasq | 2.78-r0 | — |
| Alpine v3.9 | dnsmasq | 2.78-r0 | — |
| Alpine v3.8 | dnsmasq | 2.78-r0 | — |
| Alpine v3.7 | dnsmasq | 2.78-r0 | — |
| Alpine v3.6 | dnsmasq | 2.76-r5 | — |
| Alpine v3.5 | dnsmasq | 2.76-r2 | — |
| Alpine v3.4 | dnsmasq | 2.76-r1 | — |
| Alpine v3.3 | dnsmasq | 2.76-r1 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | dnsmasq +1 | 2.76-5.amzn2 | ALAS2-2019-1251 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | dnsmasq +1 | 2.76-2.el7_4.2 | ELSA-2017-2836 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- Dnsmasq < 2.78 - Lack of free() Denial of Service EDB-42945 · dos · Oct 2, 2017 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 10
- RHSA-2017:2836 Red Hat Security Advisory: dnsmasq security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-3430-1 dnsmasq vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2017:2617-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2618-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2619-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10721-1 dnsmasq-2.86-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2616-1 Security update for dnsmasq SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2019-1251 Critical: dnsmasq security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 22, 2019
- ICSA-17-332-01 Siemens SCALANCE W1750D, M800, S615, and RUGGEDCOM RM1224 (Update C) CISA ICS & IT advisories · May 9, 2018
- ELSA-2017-2836 Critical: dnsmasq security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 2, 2017
References
- 1039474 vdb-entry
- https://www.synology.com/support/security/Synology_SA_17_59_Dnsmasq
- DSA-3989 vendor-advisory
- https://access.redhat.com/security/vulnerabilities/3199382
- 101085 vdb-entry
- USN-3430-1 vendor-advisory
- 101977 vdb-entry
- VU#973527 third-party-advisory
- GLSA-201710-27 vendor-advisory
- USN-3430-2 vendor-advisory
- [dnsmasq-discuss] 20171002 Announce: dnsmasq-2.78. mailing-list
- RHSA-2017:2836 vendor-advisory
- http://nvidia.custhelp.com/app/answers/detail/a_id/4561
- http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2017-005.txt
- http://thekelleys.org.uk/gitweb/?p=dnsmasq.git%3Ba=commit%3Bh=51eadb692a5123b9838e5a68ecace3ac579a3a45
- 42945 exploit
- http://thekelleys.org.uk/dnsmasq/CHANGELOG
- openSUSE-SU-2017:2633 vendor-advisory
- https://security.googleblog.com/2017/10/behind-masq-yet-more-dns-and-dhcp.html
- [dnsmasq-discuss] 20171002 IMPORTANT SECURITY INFORMATION. mailing-list
- https://cert-portal.siemens.com/productcert/pdf/ssa-689071.pdf