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CVE-2026-43617

CVE-2026-43617 · Rsync < 3.4.3 Authorization Bypass via Hostname Resolution

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

Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.

CVSS 6.3 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • rsync

    Versions
    • ≥ 0, < 3.4.3: Affected (semver)

    Update to 3.4.3

  • rsync Debian:12

    Versions
    • 3.2.7-1
    • 3.2.7-1+deb12u1
    • 3.2.7-1+deb12u2
    • 3.2.7-1+deb12u3
    • 3.2.7-1+deb12u4
    Affected ranges
    • ECOSYSTEM: < 3.2.7-1+deb12u5

    Update to 3.2.7-1+deb12u5

  • rsync Debian:13

    Versions
    • 3.4.1+ds1-5
    • 3.4.1+ds1-5+deb13u1
    • 3.4.1+ds1-5+deb13u2
    Affected ranges
    • ECOSYSTEM: < 3.4.1+ds1-5+deb13u3

    Update to 3.4.1+ds1-5+deb13u3

  • rsync Debian:14

    Versions
    • 3.4.1+ds1-5
    • 3.4.1+ds1-6
    • 3.4.1+ds1-7
    • 3.4.1+ds1-8~exp1
    • 3.4.2+ds1-1
    • 3.4.2+ds1-2
    Affected ranges
    • ECOSYSTEM: < 3.4.3+ds1-1

    Update to 3.4.3+ds1-1

  • rsync Ubuntu:Pro:14.04:LTS

    Versions
    • 3.0.9-4ubuntu1
    • 3.1.0-2
    • 3.1.0-2ubuntu0.1
    • 3.1.0-2ubuntu0.2
    • 3.1.0-2ubuntu0.3
    • 3.1.0-2ubuntu0.4
    • 3.1.0-2ubuntu0.4+esm1
    • 3.1.0-2ubuntu0.4+esm2
    Affected ranges
    • ECOSYSTEM: < 3.1.0-2ubuntu0.4+esm3

    Update to 3.1.0-2ubuntu0.4+esm3

  • rsync Ubuntu:Pro:16.04:LTS

    Versions
    • 3.1.1-3
    • 3.1.1-3ubuntu1
    • 3.1.1-3ubuntu1.1
    • 3.1.1-3ubuntu1.2
    • 3.1.1-3ubuntu1.3
    • 3.1.1-3ubuntu1.3+esm1
    • 3.1.1-3ubuntu1.3+esm2
    • 3.1.1-3ubuntu1.3+esm3
    • 3.1.1-3ubuntu1.3+esm4
    Affected ranges
    • ECOSYSTEM: < 3.1.1-3ubuntu1.3+esm5

    Update to 3.1.1-3ubuntu1.3+esm5

  • rsync Ubuntu:Pro:18.04:LTS

    Versions
    • 3.1.2-2
    • 3.1.2-2.1
    • 3.1.2-2.1ubuntu1
    • 3.1.2-2.1ubuntu1.1
    • 3.1.2-2.1ubuntu1.2
    • 3.1.2-2.1ubuntu1.3
    • 3.1.2-2.1ubuntu1.4
    • 3.1.2-2.1ubuntu1.5
    • 3.1.2-2.1ubuntu1.6
    • 3.1.2-2.1ubuntu1.6+esm1
    • 3.1.2-2.1ubuntu1.6+esm2
    Affected ranges
    • ECOSYSTEM: < 3.1.2-2.1ubuntu1.6+esm3

    Update to 3.1.2-2.1ubuntu1.6+esm3

  • rsync Ubuntu:Pro:20.04:LTS

    Versions
    • 3.1.3-6
    • 3.1.3-8
    • 3.1.3-8ubuntu0.1
    • 3.1.3-8ubuntu0.2
    • 3.1.3-8ubuntu0.3
    • 3.1.3-8ubuntu0.4
    • 3.1.3-8ubuntu0.5
    • 3.1.3-8ubuntu0.7
    • 3.1.3-8ubuntu0.8
    • 3.1.3-8ubuntu0.9
    Affected ranges
    • ECOSYSTEM: < 3.1.3-8ubuntu0.9+esm1

    Update to 3.1.3-8ubuntu0.9+esm1

  • rsync Ubuntu:22.04:LTS

    Versions
    • 3.2.3-4ubuntu1
    • 3.2.3-4ubuntu2
    • 3.2.3-8ubuntu1
    • 3.2.3-8ubuntu2
    • 3.2.3-8ubuntu3
    • 3.2.3-8ubuntu3.1
    • 3.2.7-0ubuntu0.22.04.2
    • 3.2.7-0ubuntu0.22.04.3
    • 3.2.7-0ubuntu0.22.04.4
    Affected ranges
    • ECOSYSTEM: < 3.2.7-0ubuntu0.22.04.6

    Update to 3.2.7-0ubuntu0.22.04.6

  • rsync Ubuntu:24.04:LTS

    Versions
    • 3.2.7-1
    • 3.2.7-1build1
    • 3.2.7-1build2
    • 3.2.7-1ubuntu1
    • 3.2.7-1ubuntu1.1
    • 3.2.7-1ubuntu1.2
    Affected ranges
    • ECOSYSTEM: < 3.2.7-1ubuntu1.4

    Update to 3.2.7-1ubuntu1.4

  • rsync Ubuntu:25.10

    Versions
    • 3.4.1+ds1-3
    • 3.4.1+ds1-4
    • 3.4.1+ds1-5
    • 3.4.1+ds1-5ubuntu1
    Affected ranges
    • ECOSYSTEM: < 3.4.1+ds1-5ubuntu1.2

    Update to 3.4.1+ds1-5ubuntu1.2

  • rsync Ubuntu:26.04:LTS

    Versions
    • 3.4.1+ds1-5ubuntu1
    • 3.4.1+ds1-6
    • 3.4.1+ds1-7
    Affected ranges
    • ECOSYSTEM: < 3.4.1+ds1-7ubuntu0.2

    Update to 3.4.1+ds1-7ubuntu0.2

Original sources

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