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CVE-2026-58050

CVE-2026-58050 · libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation

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

libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.

CVSS 8.3 · High · EPSS 0.4% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • libssh2

    Versions
    • ≥ 0, ≤ 1.11.1: Affected (semver)

    No fix published

  • libssh2 Debian:12

    Versions
    • 1.10.0-3
    Affected ranges
    • ECOSYSTEM: < 1.10.0-3+deb12u1

    Update to 1.10.0-3+deb12u1

  • libssh2 Debian:13

    Versions
    • 1.11.1-1
    • 1.11.1-1+deb13u1
    Affected ranges
    • ECOSYSTEM: < 1.11.1-1+deb13u2

    Update to 1.11.1-1+deb13u2

  • libssh2 Debian:14

    Versions
    • 1.11.1-1
    • 1.11.1-2
    • 1.11.1-3
    • 1.11.1-4
    • 1.11.1-5
    Affected ranges
    • ECOSYSTEM: < 1.11.1-6

    Update to 1.11.1-6

  • libssh2 Ubuntu:Pro:14.04:LTS

    Versions
    • 1.4.3-1
    • 1.4.3-2
    • 1.4.3-2ubuntu0.1
    • 1.4.3-2ubuntu0.2
    • 1.4.3-2ubuntu0.2+esm1
    • 1.4.3-2ubuntu0.2+esm2
    • 1.4.3-2ubuntu0.2+esm3
    Affected ranges
    • ECOSYSTEM: < 1.4.3-2ubuntu0.2+esm4

    Update to 1.4.3-2ubuntu0.2+esm4

  • libssh2 Ubuntu:Pro:16.04:LTS

    Versions
    • 1.5.0-2
    • 1.5.0-2ubuntu0.1
    • 1.5.0-2ubuntu0.1+esm1
    • 1.5.0-2ubuntu0.1+esm2
    Affected ranges
    • ECOSYSTEM: < 1.5.0-2ubuntu0.1+esm3

    Update to 1.5.0-2ubuntu0.1+esm3

  • libssh2 Ubuntu:Pro:18.04:LTS

    Versions
    • 1.8.0-1
    • 1.8.0-1ubuntu0.1
    Affected ranges
    • ECOSYSTEM: < 1.8.0-1ubuntu0.1+esm1

    Update to 1.8.0-1ubuntu0.1+esm1

  • libssh2 Ubuntu:Pro:20.04:LTS

    Versions
    • 1.8.0-2.1build1
    • 1.8.0-2.1ubuntu0.1
    Affected ranges
    • ECOSYSTEM: < 1.8.0-2.1ubuntu0.1+esm1

    Update to 1.8.0-2.1ubuntu0.1+esm1

  • libssh2 Ubuntu:22.04:LTS

    Versions
    • 1.9.0-3
    • 1.10.0-2
    • 1.10.0-2build1
    • 1.10.0-3
    Affected ranges
    • ECOSYSTEM: < 1.10.0-3ubuntu0.1

    Update to 1.10.0-3ubuntu0.1

  • libssh2 Ubuntu:24.04:LTS

    Versions
    • 1.11.0-2
    • 1.11.0-3
    • 1.11.0-4
    • 1.11.0-4.1build1
    • 1.11.0-4.1build2
    • 1.11.0-4.1ubuntu0.24.04.1
    • 1.11.0-4.1ubuntu0.24.04.2
    Affected ranges
    • ECOSYSTEM: < 1.11.0-4.1ubuntu0.24.04.3

    Update to 1.11.0-4.1ubuntu0.24.04.3

  • libssh2 Ubuntu:25.10

    Versions
    • 1.11.1-1
    • 1.11.1-1build1
    • 1.11.1-1ubuntu0.25.10.1
    • 1.11.1-1ubuntu0.25.10.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • libssh2 Ubuntu:26.04:LTS

    Versions
    • 1.11.1-1build1
    • 1.11.1-1build2
    • 1.11.1-1ubuntu0.26.04.1
    • 1.11.1-1ubuntu0.26.04.2
    Affected ranges
    • ECOSYSTEM: < 1.11.1-1ubuntu0.26.04.3

    Update to 1.11.1-1ubuntu0.26.04.3

Original sources

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