Out-of-bounds Read in Dnsmasq
CVE-2026-5172
A buffer overflow in dnsmasq’s extract_addresses() function allows an attacker to trigger a heap out-of-bounds read and crash by exploiting a malformed DNS response, enabling extract_name() to advance the pointer past the record’s end.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.007 (50.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 50.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.027 · newest: 0.007 · change: -0.020
Affected products
- Dnsmasq — versions 0, 2.93, 2.92rel2
Weakness classification (CWE)
Public proof-of-concept exploits
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-2026-5172?
- CVE-2026-5172 is a high-severity vulnerability in Dnsmasq, classified under Out-of-bounds Read. CVSS score: 7.3/10. Published 2026-05-11.
- How severe is CVE-2026-5172?
- High severity. CVSS v3 base score is 7.3 out of 10.
- Is CVE-2026-5172 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.