{"id":"AZL-93402","summary":"CVE-2026-66033 affecting package libssh2 for versions less than 1.11.1-5","details":"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.","modified":"2026-08-31T05:26:27Z","published":"2026-07-24T17:17:35Z","upstream":["CVE-2026-66033"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66033"}],"affected":[{"package":{"name":"libssh2","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/libssh2"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.11.1-5"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-93402.json"}}],"schema_version":"1.9.0"}