Use After Free Affecting c-ares package, versions *


Severity

Recommended
0.0
high
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.84% (57th percentile)

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  • Snyk IDSNYK-CENTOS6-CARES-17939090
  • published10 Jul 2026
  • disclosed7 Jul 2026

Introduced: 7 Jul 2026

CVE-2026-33630  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

There is no fixed version for Centos:6 c-ares.

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 Centos. See How to fix? for Centos:6 relevant fixed versions and status.

c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares' query-completion handling. The same flaw — a query's callback being invoked while the query is still linked in the channel's internal lookup structures — is present at multiple points in the resend/finish path (timeout handling, response handling, and query dispatch). If the query, or for ares_getaddrinfo() the owning host_query, is freed as a side effect of that callback, it is then accessed and/or freed a second time. This vulnerability is fixed in ver 1.34.7.

CVSS Base Scores

version 3.1