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CVE-2025-15661

CVE-2025-15661 · libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c

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

libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.

CVSS 8.3 · High · EPSS 0.6% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • libssh2

    Versions
    • ≥ 0, ≤ 1.11.1: Affected (semver)
    • 2dae3024897e1898d389835151f4e9606227721d: Not affected (git)

    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
    Affected ranges
    • ECOSYSTEM: < 1.11.1-1+deb13u1

    Update to 1.11.1-1+deb13u1

  • libssh2 Debian:14

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

    Update to 1.11.1-4

  • 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
    • 1.4.3-2ubuntu0.2+esm4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • 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
    • 1.5.0-2ubuntu0.1+esm3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • libssh2 Ubuntu:Pro:18.04:LTS

    Versions
    • 1.8.0-1
    • 1.8.0-1ubuntu0.1
    • 1.8.0-1ubuntu0.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • libssh2 Ubuntu:Pro:20.04:LTS

    Versions
    • 1.8.0-2.1build1
    • 1.8.0-2.1ubuntu0.1
    • 1.8.0-2.1ubuntu0.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • libssh2 Ubuntu:22.04:LTS

    Versions
    • 1.9.0-3
    • 1.10.0-2
    • 1.10.0-2build1
    • 1.10.0-3
    • 1.10.0-3ubuntu0.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • 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
    Affected ranges
    • ECOSYSTEM: < 1.11.0-4.1ubuntu0.24.04.2

    Update to 1.11.0-4.1ubuntu0.24.04.2

  • libssh2 Ubuntu:25.10

    Versions
    • 1.11.1-1
    • 1.11.1-1build1
    • 1.11.1-1ubuntu0.25.10.1
    Affected ranges
    • ECOSYSTEM: < 1.11.1-1ubuntu0.25.10.2

    Update to 1.11.1-1ubuntu0.25.10.2

  • libssh2 Ubuntu:26.04:LTS

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

    Update to 1.11.1-1ubuntu0.26.04.2

Original sources

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