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High USN-8844-1 1 CVE

c-ares vulnerability

Published Sep 29, 2026 · Updated Sep 29, 2026

Ecosystem: Ubuntu

Summary

It was discovered that c-ares incorrectly handled certain query completion
callbacks. An attacker could possibly use this issue to trigger a use-
after-free or double-free, resulting in a denial of service or arbitrary
code execution.

Fixed packages 1

ReleasePackageFixed in
Ubuntu · 26.04 LTS 26.04:LTS c-ares 1.34.6-1ubuntu0.1

Vulnerabilities 1

  • High 7.5
    CVE-2026-33630

    c-ares : Use-after-free / double-free in c-ares query-completion handling, remotely triggerable via ares_getaddrinfo() over TCP

    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 st…

    c-ares c-ares nodejs fluent-bit Debian Ubuntu Azure Linux Alpine

References

  • report
    https://ubuntu.com/security/CVE-2026-33630