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Vulnerabilities

Vulnerability · CVE-2026-69184

c-ares: CPU-exhaustion denial of service via unbounded DNS name compression pointer chains

Published Sep 18, 2026 · catalog updated Sep 21, 2026 · c-ares: CPU-exhaustion denial of

Check if you run it

No confirmed exploitation is on record for CVE-2026-69184. EPSS is 0.48%. Act only if a listed version of c-ares: CPU-exhaustion denial of is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (c-ares: CPU-exhaustion denial of).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.48%
Remediation
Advisory link
Affected products
vendor c-ares c-ares

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor c-ares c-aresversion unspecified

How to fix CVE-2026-69184

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-69184. EPSS is 0.48%. Act only if a listed version of c-ares: CPU-exhaustion denial of is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-407. EPSS 0.48%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Ubuntu security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 21, 2026 · CVE.org

    Updated

    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

  2. Oct 21, 2026 · Ubuntu Security Notices

    Detected

    CVE-2026-69184 is listed by USN-8951-1: c-ares vulnerabilities.

Sources

  • CVE.orgVulnerability recordCVE-2026-69184

    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

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-69184

    30-day exploitation probability 0.48%

    first.org
  • Ubuntu Security NoticesVendor advisoryCVE-2026-69184

    It was discovered that c-ares incorrectly parsed certain SOA replies. A remote attacker could possibly use this issue to cause c-ares to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-22217) It was discovered tha

    ubuntu.com

References

Freshness

Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.