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CVE-2026-2291 is a heap-based buffer overflow in dnsmasq DNS-name processing. The flaw occurs in the cache insertion path after names received in DNS wire format are converted to escaped C strings. The cache uses a 1,025-byte heap buffer for long names, but the vulnerable code does not validate that an escaped name fits before copying it. A malicious upstream DNS reply containing suitably constructed names can overflow the buffer. The flaw was introduced in dnsmasq 2.73 and affects the extract_name() processing path.
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1 valid exploit after Mallory filtered fakes, detection scripts, and README-only repos.
This repository is a dnsmasq vulnerability verification toolkit centered on CVE-2026-2291, CVE-2026-5172, CVE-2026-4890, CVE-2026-4891, CVE-2026-4892, and CVE-2026-4893. It is not tied to a common exploit framework. The repository contains four functional scripts plus documentation: (1) dnsmasq_cve_verify.py is the primary end-to-end black-box verifier that runs from a testing laptop, starts a malicious DNS service, sends trigger traffic to the DUT, and uses SSH to inspect dnsmasq state and logs before issuing PASS/FAIL verdicts; (2) malicious_dns_server.py is a standalone UDP DNS server that returns crafted malformed responses for manual reproduction of selected parser bugs, notably CVE-2026-5172 and DNSSEC-related issues; (3) test_dnsmasq_cve_remote.py is a lightweight remote detection script that queries version.bind over UDP/53 and infers vulnerability status from the reported dnsmasq version; and (4) test_dnsmasq_cve_on_device.sh is a shell-based local checker that runs on the target device and uses version/strings heuristics to assess patch status and feature applicability. The main exploit capability is network-based triggering of dnsmasq parsing flaws through malicious DNS responses. The code crafts malformed CNAME/rdlen combinations, DNSSEC/NSEC/RRSIG-related records, and ECS-related inputs to induce crashes, hangs, or logic bypasses in vulnerable dnsmasq builds. The README also describes a DHCPv6 CLID overflow test for CVE-2026-4892, which is a local/adjacent vector requiring DHCPv6 support and dhcp-script configuration. The repository therefore mixes active exploit-style verification with auxiliary detection scripts. Because payloads are hardcoded and purpose-built for QA verification rather than generalized post-exploitation, the maturity is best classified as OPERATIONAL rather than weaponized. Fingerprintable observables include the default DUT IP 192.168.1.1, example attacker IP 10.0.0.211, SSH on TCP/22, DNS on UDP/53, trigger domains such as crash-5172.evil.test and crash-2291.evil.test, the version.bind CHAOS TXT query, and DUT file paths like /etc/dnsmasq.conf, /tmp/resolv.conf.auto, /sbin/dnsmasq, /usr/sbin/dnsmasq, and /var/log/messages*. Overall, the repository’s purpose is QA/security validation of dnsmasq patch status and exploitability in live devices, especially routers or embedded Linux systems using dnsmasq as a DNS forwarder.
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32 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A vulnerability covered by a CentOS 8 local security-check advisory. The supplied plugin metadata identifies it as a CVSS v2 score source but does not describe the underlying flaw.
A vulnerability referenced by the Nutanix AHV Nessus plugin; individual technical details are not provided.
A specific vulnerability referenced in the EulerOS security advisory EulerOS_SA-2026-3210 affecting EulerOS dnsmasq-related packages; the content does not provide technical details beyond its inclusion in the advisory.
A specific vulnerability referenced in a Huawei EulerOS security advisory affecting dnsmasq-related packages; the content does not describe the flaw type.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.