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...

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-2026-55199 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 - 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

CVE-2026-55199 affects libssh2 up to version 1.11.1. The vulnerability lies in the SSH_MSG_EXT_INFO handler (src/packet.c), where return values from _libssh2_get_string() are unchecked. During key exchange, a malicious SSH server can set nr_extensions to 0xFFFFFFFF, causing the client to spin in ...

Unchecked Input for Loop Condition

Overview Affected versions of this package are vulnerable to Unchecked Input for Loop Condition in the SSHMSGEXTINFO handler during the initial handshake process. An attacker can cause the client application to become unresponsive by sending a crafted extension count value that triggers an infini...

PT-2026-50527

Name of the Vulnerable Software and Affected Versions libssh2 versions prior to 1.11.1 Description A pre-authentication denial of service issue exists in the SSH MSG EXT INFO handler within src/packet.c. A malicious SSH server can trigger a CPU exhaustion loop on the client by sending a crafted...

CVE-2026-9507

A session fixation vulnerability has been identified in osTicket v1.18.2. This security flaw allows an attacker to hijack a victim’s account by keeping the initial session identifier OSTSESSID active after a successful login. The issue lies in the fact that the application does not invalidate the...

BIT-PARSE-2026-47138 Parse Server: Pre-authentication denial of service via client version header regex backtracking

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.77 and 9.9.1, an unauthenticated attacker who knows a publicly-known Parse Application ID can submit a single HTTP request whose client SDK version field contains...

BIT-MONGODB-2026-9740 Unbounded recursion in BSONColumn interleaved-reference causes pre-auth stack overflow

A vulnerability in MongoDB Server's BSON validation logic allows an unauthenticated user to crash the mongod process by sending a specially crafted message. The BSON validator's handling of certain nested binary data structures permits uncontrolled mutual recursion between validation functions,...

EUVD-2026-37079

A session fixation vulnerability has been identified in osTicket v1.18.2. This security flaw allows an attacker to hijack a victim’s account by keeping the initial session identifier OSTSESSID active after a successful login. The issue lies in the fact that the application does not invalidate the...

CVE-2026-9507 Session fixation vulnerability in Enhancesoft's osTicket

A session fixation vulnerability has been identified in osTicket v1.18.2. This security flaw allows an attacker to hijack a victim’s account by keeping the initial session identifier OSTSESSID active after a successful login. The issue lies in the fact that the application does not invalidate the...

CVE-2026-9507

CVE-2026-9507 affects osTicket v1.18.2. A session fixation flaw arises because the application does not invalidate the pre-authentication cookie or generate a new identifier for the authenticated context (OSTSESSID). As a result, an attacker could set a known session ID in the victim’s browser an...

Exploit for Deserialization of Untrusted Data in Facebook React

CVE-2025-55182 - React2Shell Pre-authentication RCE in Reac...

Exploit for Embedded Malicious Code in Tukaani Xz

XZ Backdoor Labs CVE-2024-3094 Safe, hands-on labs for...

CVE-2026-53519 Nezha Monitoring: Pre-auth path traversal via /dashboard.. prefix confusion leaks jwt_secret_key

Nezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. Prior to version 2.0.13, fallbackToFrontend in the dashboard's NoRoute handler treats any URL whose raw string starts with /dashboard as an admin-frontend asset request. The check uses strings.HasPrefi...

CVE-2026-47138 Parse Server: Pre-authentication denial of service via client version header regex backtracking

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.77 and 9.9.1-alpha.1, an unauthenticated attacker who knows a publicly-known Parse Application ID can submit a single HTTP request whose client SDK version field contains...

CVE-2026-47138 Parse Server: Pre-authentication denial of service via client version header regex backtracking

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.77 and 9.9.1-alpha.1, an unauthenticated attacker who knows a publicly-known Parse Application ID can submit a single HTTP request whose client SDK version field contains...