Out-of-bounds Read in Dnsmasq
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.008 (56.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.064 · newest: 0.008 · change: -0.056
Affected products
- Dnsmasq — versions 0, 2.93, 2.92rel2
Weakness classification (CWE)
References
- thekelleys.org.uk/dnsmasq/
- www.kb.cert.org/vuls/id/471747
- lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html
- thekelleys.org.uk/dnsmasq/CVE/
- github.com/NixOS/nixpkgs/pull/519082
- github.com/NixOS/nixpkgs/pull/519093
- github.com/pi-hole/FTL/releases/tag/v6.6.2
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-4891?
- CVE-2026-4891 is a medium-severity vulnerability in Dnsmasq, classified under Out-of-bounds Read. CVSS score: 5.3/10. Published 2026-05-11.
- How severe is CVE-2026-4891?
- Medium severity. CVSS v3 base score is 5.3 out of 10.