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CVE-2026-33254

CVE-2026-33254 · Resource exhaustion via DoQ/DoH3 connections

This page contains facts from public vulnerability sources. Check the original advisory before updating.

An attacker can create a large number of concurrent DoQ or DoH3 connections, causing unlimited memory allocation in DNSdist and leading to a denial of service. DOQ and DoH3 are disabled by default.

CVSS 5.3 · Medium · EPSS 0.8% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • dnsdist

    Versions
    • ≥ 1.9.0, < 1.9.13: Affected (semver)
    • ≥ 2.0.0, < 2.0.4: Affected (semver)

    Update to 1.9.13; Update to 2.0.4

  • dnsdist Debian:12

    Versions
    • 1.7.3-2
    • 1.8.0-1
    • 1.8.1-1
    • 1.8.2-1
    • 1.8.2-2
    • 1.8.2-3
    • 1.8.3-1
    • 1.8.3-2
    • 1.8.3-3
    • 1.9.10-1
    • 1.9.3-1
    • 1.9.4-1
    • 1.9.5-1
    • 1.9.6-1
    • 1.9.8-1
    • 1.9.9-1
    • 2.0.0-1
    • 2.0.0-2
    • 2.0.0-3
    • 2.0.0-4
    • 2.0.0-5
    • 2.0.0-6
    • 2.0.0~rc1-1
    • 2.0.0~rc1-2
    • 2.0.0~rc2-1
    • 2.0.1-1
    • 2.0.2-1
    • 2.0.3-1
    • 2.0.4-1
    • 2.0.5-1
    • 2.0.5-2
    • 2.0.5-3
    • 2.0.6-1
    • 2.1.0-1
    • 2.1.0-2
    • 2.1.1-1
    • 2.1.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Debian:13

    Versions
    • 1.9.10-1
    • 1.9.10-1+deb13u1
    Affected ranges
    • ECOSYSTEM: < 1.9.14-0+deb13u1

    Update to 1.9.14-0+deb13u1

  • dnsdist Debian:14

    Versions
    • 1.9.10-1
    • 2.0.0-1
    • 2.0.0-2
    • 2.0.0-3
    • 2.0.0-4
    • 2.0.0-5
    • 2.0.0-6
    • 2.0.0~rc1-1
    • 2.0.0~rc1-2
    • 2.0.0~rc2-1
    • 2.0.1-1
    • 2.0.2-1
    • 2.0.3-1
    Affected ranges
    • ECOSYSTEM: < 2.0.4-1

    Update to 2.0.4-1

  • dnsdist Ubuntu:16.04:LTS

    Versions
    • 1.0.0~alpha2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Ubuntu:Pro:18.04:LTS

    Versions
    • 1.2.0-1
    • 1.2.0-3
    • 1.2.1-1
    • 1.2.1-1build1
    • 1.2.1-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Ubuntu:Pro:20.04:LTS

    Versions
    • 1.4.0~rc3-1
    • 1.4.0-1
    • 1.4.0-1build1
    • 1.4.0-1build2
    • 1.4.0-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Ubuntu:Pro:22.04:LTS

    Versions
    • 1.5.1-3build2
    • 1.6.1-1build1
    • 1.6.1-1ubuntu0.1~esm1
    • 1.6.1-1ubuntu0.1~esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Ubuntu:Pro:24.04:LTS

    Versions
    • 1.8.0-1
    • 1.8.2-1
    • 1.8.2-2
    • 1.8.2-3
    • 1.8.3-1
    • 1.8.3-2
    • 1.8.3-2build1
    • 1.8.3-2build2
    • 1.8.3-2ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Ubuntu:25.10

    Versions
    • 1.9.8-1
    • 1.9.10-1
    • 1.9.10-1ubuntu0.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Ubuntu:26.10

    Versions
    • 2.0.2-1build1
    • 2.0.5-2ubuntu1
    • 2.0.5-2ubuntu3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • dnsdist Ubuntu:26.04:LTS

    Versions
    • 1.9.10-1
    • 2.0.1-1
    • 2.0.2-1
    • 2.0.2-1build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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