dnsmasq’s extract_name() function contains a heap buffer overflow that can be triggered by specially crafted DNS queries. The overflow can overwrite portions of the DNS cache, allowing an attacker to insert arbitrary domain‑to‑IP mappings. This can redirect traffic to malicious hosts or, if exploited to corrupt critical cache entries, interrupt DNS resolution for clients, effectively causing a denial of service.

The vulnerability applies to the dnsmasq daemon. The advisory does not list specific version numbers, so all deployments of dnsmasq are considered potentially vulnerable until a release that removes the flaw is installed. System administrators should verify the version of dnsmasq running on each DNS host and compare it against vendor updates.

The EPSS score is < 1% and the vulnerability is not listed in CISA’s KEV catalog, so the exploitation probability is low but non‑zero. However, the flaw is reachable via network‑attached DNS queries, requires no local privilege, and provides a direct remote attack path to alter DNS cache contents or crash the service. Because the attack can happen from any remote host that can send DNS packets to the daemon, the risk is significant for exposed DNS servers that do not employ strict access controls or additional validation.