CVE-2026-66033 - CERT CVE
ID CVE-2026-66033
Sažetak 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.
Reference
CVSS
Base: 7.5
Impact: 3.6
Exploitability:3.9
Pristup
VektorSloženostAutentikacija
NETWORK LOW NONE
Impact
PovjerljivostCjelovitostDostupnost
NONE NONE HIGH
CVSS vektor CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Zadnje važnije ažuriranje 28-07-2026 - 16:09
Objavljeno 24-07-2026 - 17:17