CVE catalog
CVE-2026-4891
A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 6.41% · Oct 25, 2026
A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | dnsmasq | sid | 2.93-3 | fixed |
| Debian | dnsmasq | forky | 2.93-3 | fixed |
| Debian | dnsmasq | trixie | 2.91-1+deb13u2 | fixed |
| Debian | dnsmasq | trixie-security | 2.91-1+deb13u1 | fixed |
| Debian | dnsmasq | bookworm | 2.90-4~deb12u2 | fixed |
| Debian | dnsmasq | bookworm-security | 2.90-4~deb12u2 | fixed |
| Cpe | dnsmasq | Not reported | 2.90-2ubuntu0.3 | fixed |
| Cpe | dnsmasq-base | Not reported | 2.90-2ubuntu0.3 | fixed |
| Cpe | dnsmasq-base-lua | Not reported | 2.90-2ubuntu0.3 | fixed |
| Cpe | dnsmasq-utils | Not reported | 2.90-2ubuntu0.3 | fixed |
| Cpe | dnsmasq | Not reported | 2.90-4~deb12u2 | fixed |
| Alpine | dnsmasq | 3.22 | 2.91-r1 | fixed |
| Alpine | dnsmasq | 3.23 | 2.91-r1 | fixed |
| Alpine | dnsmasq | 3.24 | 2.92_p2-r0 | fixed |
| Ubuntu | dnsmasq | pro | 2.80-1ubuntu2 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1ubuntu4 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1.1ubuntu1 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1.1ubuntu1.2 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1.1ubuntu1.3 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1.1ubuntu1.4 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1.1ubuntu1.5 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1.1ubuntu1.6 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.80-1.1ubuntu1.7 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.90-0ubuntu0.20.04.1 | vulnerable |
| Ubuntu | dnsmasq | pro | 2.90-0ubuntu0.20.04.1+esm2 | fixed |
| Ubuntu | dnsmasq | 22.04 | 2.85-1ubuntu2 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.86-1.1 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.86-1.1ubuntu0.1 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.86-1.1ubuntu0.2 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.86-1.1ubuntu0.3 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.86-1.1ubuntu0.4 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.86-1.1ubuntu0.5 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.90-0ubuntu0.22.04.1 | vulnerable |
| Ubuntu | dnsmasq | 22.04 | 2.90-0ubuntu0.22.04.3 | fixed |
| Ubuntu | dnsmasq | 24.04 | 2.89-1 | vulnerable |
| Ubuntu | dnsmasq | 24.04 | 2.90-2 | vulnerable |
| Ubuntu | dnsmasq | 24.04 | 2.90-2build1 | vulnerable |
| Ubuntu | dnsmasq | 24.04 | 2.90-2build2 | vulnerable |
| Ubuntu | dnsmasq | 24.04 | 2.90-2ubuntu0.1 | vulnerable |
| Ubuntu | dnsmasq | 24.04 | 2.90-2ubuntu0.3 | fixed |
| Ubuntu | dnsmasq | 25.10 | 2.91-1 | vulnerable |
| Ubuntu | dnsmasq | 25.10 | 2.91-1build1 | vulnerable |
| Ubuntu | dnsmasq | 25.10 | 2.91-1ubuntu0.2 | fixed |
| Ubuntu | dnsmasq | 26.04 | 2.91-1build1 | vulnerable |
| Ubuntu | dnsmasq | 26.04 | 2.92~rc3-1 | vulnerable |
| Ubuntu | dnsmasq | 26.04 | 2.92-1 | vulnerable |
| Ubuntu | dnsmasq | 26.04 | 2.92-1ubuntu0.2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | dnsmasq | source | sid | 2.92-5 | not yet assigned | Not reported | Not reported |
| Debian | dnsmasq | source | forky | 2.92-5 | not yet assigned | Not reported | Not reported |
| Debian | dnsmasq | source | trixie | 2.91-1+deb13u1 | not yet assigned | Not reported | Not reported |
| Debian | dnsmasq | source | bookworm | 2.90-4~deb12u2 | not yet assigned | Not reported | Not reported |
| Cpe | dnsmasq | cpe | Not reported | 2.90-2ubuntu0.3 | Not reported | Not reported | Not reported |
| Cpe | dnsmasq-base | cpe | Not reported | 2.90-2ubuntu0.3 | Not reported | Not reported | Not reported |
| Cpe | dnsmasq-base-lua | cpe | Not reported | 2.90-2ubuntu0.3 | Not reported | Not reported | Not reported |
| Cpe | dnsmasq-utils | cpe | Not reported | 2.90-2ubuntu0.3 | Not reported | Not reported | Not reported |
| Cpe | dnsmasq | cpe | Not reported | 2.90-4~deb12u2 | Not reported | Not reported | Not reported |
| Alpine | dnsmasq | apk | 3.22 | 2.91-r1 | Not reported | ALPINE-CVE-2026-4891 | Not reported |
| Alpine | dnsmasq | apk | 3.23 | 2.91-r1 | Not reported | ALPINE-CVE-2026-4891 | Not reported |
| Alpine | dnsmasq | apk | 3.24 | 2.92_p2-r0 | Not reported | ALPINE-CVE-2026-4891 | Not reported |
| Ubuntu | dnsmasq | deb | pro | 2.90-0ubuntu0.20.04.1+esm2 | Not reported | UBUNTU-CVE-2026-4891 | Not reported |
| Ubuntu | dnsmasq | deb | 22.04 | 2.90-0ubuntu0.22.04.3 | Not reported | UBUNTU-CVE-2026-4891 | Not reported |
| Ubuntu | dnsmasq | deb | 24.04 | 2.90-2ubuntu0.3 | Not reported | UBUNTU-CVE-2026-4891 | Not reported |
| Ubuntu | dnsmasq | deb | 25.10 | 2.91-1ubuntu0.2 | Not reported | UBUNTU-CVE-2026-4891 | Not reported |
| Ubuntu | dnsmasq | deb | 26.04 | 2.92-1ubuntu0.2 | Not reported | UBUNTU-CVE-2026-4891 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [dnsmasq]Fixed
Details (4)
2.90-4~deb12u2· all · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· all · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· all · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· all · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
- [dnsmasq-base]Fixed
Source package: [dnsmasq]
Details (4)
2.90-4~deb12u2· amd64 · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· amd64 · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
- [dnsmasq-base-lua]Fixed
Source package: [dnsmasq]
Details (4)
2.90-4~deb12u2· amd64 · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· amd64 · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
- [dnsmasq-utils]Fixed
Source package: [dnsmasq]
Details (4)
2.90-4~deb12u2· amd64 · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookwormFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· amd64 · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookworm-securityFixed · Fixed:
2.90-4~deb12u2nvd · dnsmasq · debian · bookworm; nvd · dnsmasq · debian · 12
[Debian 13 (Trixie)]
- [dnsmasq]Fixed
Details (4)
2.91-1+deb13u1· all · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· all · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· all · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· all · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
- [dnsmasq-base]Fixed
Source package: [dnsmasq]
Details (4)
2.91-1+deb13u1· amd64 · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· amd64 · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
- [dnsmasq-base-lua]Fixed
Source package: [dnsmasq]
Details (4)
2.91-1+deb13u1· amd64 · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· amd64 · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
- [dnsmasq-utils]Fixed
Source package: [dnsmasq]
Details (4)
2.91-1+deb13u1· amd64 · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixieFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· amd64 · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixie-securityFixed · Fixed:
2.91-1+deb13u1nvd · dnsmasq · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/rhsa-2026_34508.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-4891]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-4891]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-4891]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-4891]
- [https://security-tracker.debian.org/tracker/CVE-2026-4891]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4891.json]
- [https://ubuntu.com/security/notices/USN-8268-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1468.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]