CVE-2026-69184: C-Ares

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_name_parse() enforces backward DNS compression pointers but does not bound the total pointer hops or assembled name length. A malicious DNS server can send a response containing a long descending pointer chain and many resource records whose NAME or RDATA fields refer to the chain, causing repeated decompression work that grows quadratically with message size. A single crafted response can stall the single-threaded c-ares event loop and deny DNS resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7.

Affected products

• C-Ares C-Ares: before 1.34.7 (fixed in 1.34.7)

Published 2026-09-18. Last modified 2026-09-24.