CVE-2026-66033
libssh2 libssh2 취약점
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.
- 대응 우선순위
- 점검
- CVSS
- 8.7
- EPSS
- - 백분위 -
- CISA KEV
- 미등록
- 조치 기한
- -
- 공개일
- 2026.07.25