C-ares is a technology platform tracked across 1 threat cluster and 1 intelligence report mention on ThreatCluster. First observed December 11, 2025; most recent activity December 11, 2025.
C-ares is an asynchronous DNS resolver library used by many networking applications to perform non-blocking DNS lookups. It is widely embedded in software stacks and Linux distributions, making its security posture a high-priority concern for defenders. Vulnerabilities in c-ares can impact DNS query handling and, depending on the flaw, may be exploited to disrupt service or compromise components that rely on DNS resolution.
A security issue has been identified in the c-ares library affecting Ubuntu 25.10 and 25.04. The vulnerability allows an attacker to cause c-ares to crash by sending specially crafted queries, leading to a denial of…