Algorithmic Complexity Affecting c-ares package, versions <1.18.1-1ubuntu0.22.04.4


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.48% (41st percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UBUNTU2204-CARES-18760225
  • published20 Oct 2026
  • disclosed18 Sept 2026

Introduced: 18 Sep 2026

CVE-2026-69184  (opens in a new tab)
CWE-407  (opens in a new tab)

How to fix?

Upgrade Ubuntu:22.04 c-ares to version 1.18.1-1ubuntu0.22.04.4 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream c-ares package and not the c-ares package as distributed by Ubuntu. See How to fix? for Ubuntu:22.04 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1