CVE-2026-5172
Heap Out-of-Bounds Read in Dnsmasq DNS Response Handling
Publication date: 2026-05-11
Last updated on: 2026-05-11
Assigner: CERT/CC
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| the_dnsmasq_project | dnsmasq | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
What immediate steps should I take to mitigate this vulnerability?
To mitigate the vulnerability CVE-2026-5172 in dnsmasq, you should update dnsmasq to the patched version 2.92rel2 or later, which includes fixes for this and other related vulnerabilities.
The patched version 2.92rel2 is available from the official dnsmasq website and has been incorporated into various package repositories, including NixOS.
Applying this update promptly will address the buffer overflow issue in the extract_addresses() function and prevent potential heap out-of-bounds reads and crashes caused by malformed DNS responses.
Can you explain this vulnerability to me?
This vulnerability is a buffer overflow in the extract_addresses() function of dnsmasq. It allows an attacker to cause a heap out-of-bounds read and crash the program by sending a malformed DNS response. The issue arises because the extract_name() function advances the pointer beyond the end of the DNS record.
How can this vulnerability impact me? :
The vulnerability can lead to a crash of the dnsmasq service due to a heap out-of-bounds read triggered by a malformed DNS response. This can cause denial of service, potentially disrupting network services that rely on dnsmasq for DNS resolution.