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CVE-2026-42389

CVE-2026-42389 · Reject more queries with invalid header values

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

This fix provides extra hardening for the 5.4.x branch by doing extra validation of incoming answers from authoritative servers.

CVSS 5.3 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • recursor

    Versions
    • ≥ 5.4.0, < 5.4.3: Affected (semver)

    Update to 5.4.3

  • pdns-recursor Debian:14

    Versions
    • 5.2.4-2
    • 5.2.5-1
    • 5.3.0-1
    • 5.3.0-2
    • 5.3.0-3
    • 5.3.0-4
    • 5.3.0-5
    • 5.3.1-1
    • 5.3.3-1
    • 5.3.4-1
    • 5.3.4-2
    • 5.3.5-1
    • 5.4.0-1
    • 5.4.1-1
    • 5.4.1-2
    • 5.4.2-1
    • 5.4.2-2
    Affected ranges
    • ECOSYSTEM: < 5.4.3-1

    Update to 5.4.3-1

  • pdns-recursor Ubuntu:Pro:16.04:LTS

    Versions
    • 3.7.3-1
    • 4.0.0~alpha1-1
    • 4.0.0~alpha1-2
    • 4.0.0~alpha2-2
    • 4.0.0~alpha2-2ubuntu0.1
    • 4.0.0~alpha2-2ubuntu0.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pdns-recursor Ubuntu:Pro:18.04:LTS

    Versions
    • 4.0.6-1
    • 4.0.6-1build1
    • 4.0.7-1
    • 4.1.1-1
    • 4.1.1-1build1
    • 4.1.1-2
    • 4.1.1-2ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pdns-recursor Ubuntu:Pro:20.04:LTS

    Versions
    • 4.2.0-6
    • 4.2.1-1
    • 4.2.1-1build1
    • 4.2.1-1build2
    • 4.2.1-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pdns-recursor Ubuntu:Pro:22.04:LTS

    Versions
    • 4.4.2-3
    • 4.6.0-1ubuntu1
    • 4.6.0-1ubuntu1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pdns-recursor Ubuntu:24.04:LTS

    Versions
    • 4.9.0-2
    • 4.9.1-4
    • 4.9.2-1
    • 4.9.2-1build1
    • 4.9.2-2
    • 4.9.3-1
    • 4.9.3-1build2
    • 4.9.3-1build3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pdns-recursor Ubuntu:25.10

    Versions
    • 5.2.0-5
    • 5.2.2-1
    • 5.2.2-2
    • 5.2.4-2
    • 5.2.4-2build2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pdns-recursor Ubuntu:26.10

    Versions
    • 5.3.5-1
    • 5.4.3-1
    • 5.4.5-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pdns-recursor Ubuntu:26.04:LTS

    Versions
    • 5.2.4-2build2
    • 5.3.1-1
    • 5.3.3-1
    • 5.3.4-1
    • 5.3.4-1build1
    • 5.3.4-2
    • 5.3.5-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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