Description (CNA)
A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| dnsmasq / dnsmasq | affected 0 before 2.92rel2 |
CWE
No CWE identifiers supplied.
References
- https://www.kb.cert.org/vuls/id/471747
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html
- https://thekelleys.org.uk/dnsmasq/CVE/
- https://github.com/NixOS/nixpkgs/pull/519093
- https://github.com/NixOS/nixpkgs/pull/519082
- https://github.com/pi-hole/FTL/releases/tag/v6.6.2
ADP enrichment
No English description supplied.
No references supplied.
A denial of service vulnerability was discovered in dnsmasq's DNSSEC validation. When parsing NSEC and NSEC3 bitmap records, the window iteration logic fails to account for the 2-byte window header when advancing through the bitmap data. A specially crafted DNS response with a zero-length bitmap can cause an infinite loop, making dnsmasq unresponsive to all queries.
- https://access.redhat.com/security/cve/CVE-2026-4890
- https://bugzilla.redhat.com/show_bug.cgi?id=2458516
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4890.json
- https://access.redhat.com/errata/RHSA-2026:40762
- https://access.redhat.com/errata/RHSA-2026:19158
- https://access.redhat.com/errata/RHSA-2026:20589
- https://access.redhat.com/errata/RHSA-2026:34508
- https://access.redhat.com/errata/RHSA-2026:19373