Denial of Service Vulnerability in c-ares Library by c-ares Development Team
CVE-2026-69184

7.5HIGH

Key Information:

Vendor

C-ares

Status
C-ares
Vendor
CVE Published:
18 September 2026

What is CVE-2026-69184?

The c-ares library, an asynchronous DNS resolver, is vulnerable to a denial of service issue due to improper handling of DNS compression pointers. Specifically, before version 1.34.7, the function ares_dns_name_parse() does not limit the total number of hops made through DNS compression, allowing a malicious DNS server to exploit this behavior. An attacker can craft a response with a long sequence of compressed DNS pointers, potentially triggering an accumulation of processing work that can significantly degrade performance or stall the c-ares event loop. This flaw does not entail memory corruption or information leakage but can severely impact DNS resolution capabilities. The vulnerability has been addressed in c-ares version 1.34.7.

Affected Version(s)

c-ares < 1.34.7

References

https://github.com/c-ares/c-ares/security/advisories/GHSA...
x_refsource_CONFIRM
https://github.com/c-ares/c-ares/pull/1164
x_refsource_MISC
https://github.com/c-ares/c-ares/pull/1210
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.