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.
History

Wed, 23 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-770
References
Metrics threat_severity

None

threat_severity

Important


Mon, 21 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sun, 20 Sep 2026 04:00:00 +0000

Type Values Removed Values Added
First Time appeared C-ares
C-ares c-ares
Vendors & Products C-ares
C-ares c-ares

Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Description 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.
Title c-ares: CPU-exhaustion denial of service via unbounded DNS name compression pointer chains
Weaknesses CWE-407
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-09-18T17:26:52.210Z

Updated: 2026-09-21T20:48:59.663Z

Reserved: 2026-08-03T16:00:23.482Z

Link: CVE-2026-69184

cve-icon Vulnrichment

Updated: 2026-09-18T20:13:19.942Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-18T18:17:11.477

Modified: 2026-09-24T21:16:28.120

Link: CVE-2026-69184

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-18T17:26:52Z

Links: CVE-2026-69184 - Bugzilla