Skip to content
OpenAdvisories

Vendor

libssh2

9 known vulnerabilities.

libssh2 at a glance

Last 12 months
9
Critical · all time
0
Exploited · all time
0
Public exploit · all time
1
New vulnerabilities per month · last 12 months
0 3 5 December 2025: 0 vulnerabilities Dec 2025 January 2026: 0 vulnerabilities February 2026: 0 vulnerabilities March 2026: 0 vulnerabilities Mar April 2026: 0 vulnerabilities May 2026: 0 vulnerabilities June 2026: 5 vulnerabilities Jun July 2026: 4 vulnerabilities August 2026: 0 vulnerabilities September 2026: 0 vulnerabilities Sep October 2026: 0 vulnerabilities November 2026: 0 vulnerabilities
Show as table
MonthVulnerabilitiesCritical
Nov 202600
Oct 202600
Sep 202600
Aug 202600
Jul 202640
Jun 202650
May 202600
Apr 202600
Mar 202600
Feb 202600
Jan 202600
Dec 202500
Nov 202500
Oct 202500
Sep 202500
Aug 202500
Jul 202500
Jun 202500
May 202500
Apr 202500
Mar 202500
Feb 202500
Jan 202500
Dec 202400

Products

Latest advisories

  • High max 8.1
    NCSC-2026-0210 2 CVEs rev. 2

    Kwetsbaarheden verholpen in libssh2 door libssh

    libssh heeft kwetsbaarheden verholpen in libssh2 tot en met versie 1.11.1.

    first Jun 23, 2026

9 results · Feed

  • High 7.5

    libssh2 Heap Buffer Overflow via ETM Cipher Negotiation

    libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packet_length smaller than the ci…

  • High 7.5

    libssh2 Heap Out-of-Bounds Read via publickey subsystem

    libssh2 through 1.11.1, fixed in commit a13bb6c, contains a missing bounds check vulnerability that allows a malicious SSH server to trigger an arbitrary-length heap out-of-bounds read and a free of an uninitialized pointer via the publickey subsystem. In lib…

  • High 7.5

    libssh2 Integer Underflow DoS via AES-GCM Cipher Negotiation

    libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2_cipher_crypt() function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM cipher…

  • High 8.8

    libssh2 Double-Free Heap Corruption via sftp_open()

    libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds …

  • Medium 6.5

    libssh2 - Free of Uninitialized Pointer in publickey List Cleanup

    libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A ma…

  • High 7.0

    libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation

    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 ove…

  • Medium 6.5

    libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c

    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 …

  • High 8.1
    CVE-2026-55200 Public exploit

    libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c

    libssh2 1.11.1, fixed in commit 97acf3d, contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length value…

  • Medium 5.9

    libssh2 - Pre-Authentication DoS via SSH_MSG_EXT_INFO Handler

    libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSH_MSG_EXT_INFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extens…