c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_parse() trusts the attacker-controlled ANCOUNT, NSCOUNT, and ARCOUNT fields before confirming that the DNS response contains enough bytes for the claimed records. Because process_answer() invokes parsing before transaction ID and question validation, a malicious DNS response can cause ares_dns_record_rr_prealloc() and ares_array_set_size() to reserve disproportionate heap memory for a tiny message. Repeated responses create large allocation and release cycles that can degrade or deny name resolution, without causing memory corruption or information disclosure. This issue is fixed in version 1.34.7.
References
Configurations
No configuration.
History
18 Sep 2026, 20:17
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/c-ares/c-ares/security/advisories/GHSA-jv8r-gqr9-68wj - |
18 Sep 2026, 18:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-09-18 18:17
Updated : 2026-09-23 18:12
NVD link : CVE-2026-69186
Mitre link : CVE-2026-69186
CVE.ORG link : CVE-2026-69186
JSON object : View
Products Affected
No product.
CWE
CWE-400
Uncontrolled Resource Consumption
