PT-2026-50786

Name of the Vulnerable Software and Affected Versions libssh2 versions prior to 1.11.1 commit 2dae302 Description An out-of-bounds heap read exists in the sftp symlink function within src/sftp.c. A malicious SSH server or man-in-the-middle attacker can disclose heap memory contents or cause a cra...

DEBIAN-CVE-2026-55199

libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...

ALPINE-CVE-2026-55200

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

ALPINE-CVE-2026-55199

libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...

DEBIAN-CVE-2026-55200

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

CVE-2026-55200

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

UBUNTU-CVE-2026-55200

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

UBUNTU-CVE-2026-55199

libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...

CVE-2026-55200 libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

EUVD-2026-37784

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

CVE-2026-55200 libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

CVE-2026-55200

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

CVE-2026-55200

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

CVE-2026-55200

CVE-2026-55200 affects libssh2 up to version 1.11.1. The vulnerability is an out-of-bounds write in ssh2_transport_read() caused by failure to enforce upper bounds on packet_length, allowing remote attackers to send crafted SSH packets to corrupt heap memory and achieve remote code execution. The...

CVE-2026-55200 libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c

libssh2 through 1.11.1, fixed in commit 7acf3df contains an out-of-bounds write vulnerability in ssh2transportread that fails to enforce upper bounds on packetlength field. Remote attackers can send crafted SSH packets with excessively large packetlength values to corrupt heap memory and achieve...

CVE-2026-55199 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 SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...

CVE-2026-55199 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 SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...

EUVD-2026-37782

libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...

CVE-2026-55199

libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...

CVE-2026-55199

libssh2 through 1.11.1, fixed in commit 1762685, contains a pre-authentication denial of service vulnerability in the SSHMSGEXTINFO handler in src/packet.c that allows a malicious SSH server to cause a client CPU exhaustion loop by sending a crafted extension count value. A malicious server can s...