PT-2026-50786 · Libssh2 · Libssh2

Joshua Rogers + 1 · Published 2026-06-18 · Updated 2026-06-18 · CVE-2025-15661

Mitre

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H

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.

Fix

Out of bounds Read

Weakness Enumeration

CWE-125

Related Identifiers

CVE-2025-15661

Affected Products

Libssh2

References · 5

• https://github.com/libssh2/libssh2/commit/2dae3024897e1898d389835151f4e9606227721d · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2025-15661 · Security Note
• https://github.com/libssh2/libssh2/pull/1717 · Note
• https://github.com/libssh2/libssh2/pull/1705 · Note
• https://vulncheck.com/advisories/libssh2-heap-buffer-over-read-via-sftp-symlink-in-sftp-c · Note