CVE-2026-4891
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 6.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Details
- Published
- Last modified
- Exploit probability
- 6.4% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Awaiting Analysis
Attack profile CVSS 3.1 · 5.3
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Fix and advisories
- https://github.com/NixOS/nixpkgs/pull/519082
- https://github.com/NixOS/nixpkgs/pull/519093
- https://github.com/pi-hole/FTL/releases/tag/v6.6.2
References
- https://github.com/NixOS/nixpkgs/pull/519082
- https://github.com/NixOS/nixpkgs/pull/519093
- https://github.com/pi-hole/FTL/releases/tag/v6.6.2
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html
- https://thekelleys.org.uk/dnsmasq/CVE/
- https://www.kb.cert.org/vuls/id/471747
- https://access.redhat.com/errata/RHSA-2026:19158
- https://access.redhat.com/errata/RHSA-2026:19373
- https://access.redhat.com/errata/RHSA-2026:20589
- https://access.redhat.com/errata/RHSA-2026:34508
- https://access.redhat.com/errata/RHSA-2026:40762
- https://access.redhat.com/security/cve/CVE-2026-4891
- https://bugzilla.redhat.com/show_bug.cgi?id=2458517
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4891.json