CVE-2026-66032 libssh2 Double-Free Heap Corruption via sftp_open()

libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftpopen function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSHFXPOPEN with SSHFXPSTATUS containin...