CVE-2025-15661: LIBSSH2

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.

Affected products

• LIBSSH2 LIBSSH2: up to and including 1.11.1

Published 2026-06-18. Last modified 2026-10-05.