CVE-2026-4891

MEDIUMNVD 5.35.3—

5.3

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.

CVSS v3: 5.3
EG Score: 5.3(high)
EPSS: 21.6%
KEV: Not listed

Published

May 11, 2026

Last Modified

May 12, 2026

Advisory Details (6)

Auto-updated May 12, 2026

No patch confirmed yet. Sources: cert.

cert

VU#471747 - dnsmasq contains several vulnerabilities, including attacker DNS redirect, privilege escalation, and heap manipulation

https://www.kb.cert.org/vuls/id/471747

generic

Index of /dnsmasq/CVE

https://thekelleys.org.uk/dnsmasq/CVE/

generic

[Dnsmasq-discuss] Security - IMPORTANT

https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html

generic

Release Pi-hole FTL v6.6.2 · pi-hole/FTL · GitHub

https://github.com/pi-hole/FTL/releases/tag/v6.6.2

generic

[Backport release-25.11] dnsmasq: 2.92 -> 2.92rel2 by LeSuisse · Pull Request #519093 · NixOS/nixpkgs · GitHub

https://github.com/NixOS/nixpkgs/pull/519093

generic

dnsmasq: 2.92 -> 2.92rel2 by LeSuisse · Pull Request #519082 · NixOS/nixpkgs · GitHub

https://github.com/NixOS/nixpkgs/pull/519082

Vendor Advisories for CVE-2026-4891(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

CVE-2026-4891
Microsoft Security Response Center (MSRC)
CVE-2026-4891

Frequently asked(5)

What is CVE-2026-4891?

CVE-2026-4891 is a medium vulnerability published on May 11, 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.

When was CVE-2026-4891 disclosed?

CVE-2026-4891 was first published in the National Vulnerability Database on May 11, 2026, with the most recent update on May 12, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-4891 actively exploited?

CVE-2026-4891 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-4891?

CVE-2026-4891 has a CVSS v3 base score of 5.3 (NVD).

How do I remediate CVE-2026-4891?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4891, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-4891

Explore →

Is Your Infrastructure Affected by CVE-2026-4891?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2026-4891

📅 Published

🔄 Last Modified

📋 Advisory Details (6)

VU#471747 - dnsmasq contains several vulnerabilities, including attacker DNS redirect, privilege escalation, and heap manipulation

Index of /dnsmasq/CVE

[Dnsmasq-discuss] Security - IMPORTANT

Release Pi-hole FTL v6.6.2 · pi-hole/FTL · GitHub

[Backport release-25.11] dnsmasq: 2.92 -> 2.92rel2 by LeSuisse · Pull Request #519093 · NixOS/nixpkgs · GitHub

dnsmasq: 2.92 -> 2.92rel2 by LeSuisse · Pull Request #519082 · NixOS/nixpkgs · GitHub

📣 Vendor Advisories for CVE-2026-4891(1)

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-4891?

🔗 Related CVEs(same product + same vendor)

Same vendor

Published

Last Modified

Advisory Details (6)

Vendor Advisories for CVE-2026-4891(1)

Frequently asked(5)

Related CVEs(same product + same vendor)