CVE-2026-66033

Published: Lug 24, 2026 Last Modified: Lug 24, 2026

ExploitDB:

Other exploit source:

Google Dorks:

HIGH 8,7

Source: [email protected]

Attack Vector: network

Attack Complexity: low

Privileges Required: none

User Interaction: none

Confidentiality: N/A

Integrity: N/A

Availability: N/A

HIGH 7,5

Source: [email protected]

Attack Vector: network

Attack Complexity: low

Privileges Required: none

User Interaction: none

Scope: unchanged

Confidentiality: none

Integrity: none

Availability: high

Description

AI Translation Available

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 ciphers during handshake. Attackers can exploit the underflow in the expression computing blocksize minus aadlen minus authentication tag length to trigger an out-of-bounds read and a memcpy call with a near-SIZE_MAX length argument, causing immediate process crash before any authentication occurs.

125

Out-of-bounds Read

Draft

Abstraction: Base Structure: Simple

Common Consequences

Security Scopes Affected:

Confidentiality Availability Other

Potential Impacts:

Read Memory Bypass Protection Mechanism Dos: Crash, Exit, Or Restart Varies By Context

Applicable Platforms

Languages: Memory-Unsafe, C, C++

Technologies: ICS/OT

View CWE Details

191

Integer Underflow (Wrap or Wraparound)

Draft

Abstraction: Base Structure: Simple

Common Consequences

Security Scopes Affected:

Availability Integrity Confidentiality Access Control

Potential Impacts:

Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Instability Modify Memory Execute Unauthorized Code Or Commands Bypass Protection Mechanism