CVE-2025-15661
Published: June 23, 2026Last modified: July 8, 2026
Description
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.5 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | LOW |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | libssh2 | Fixed (1.11.1-r2) |
| 25 LTS | libssh2 | Fixed (1.11.1-r3) | |
| Stream | libssh2 | Fixed (1.11.1-r4) | |
| rust | Fixed (1.96.1-r0) |