CVE-2025-15661

HIGH EPSS 18.2%
Published Jun 18, 20261w ago · Modified Jun 22, 20261w ago
8.3 CVSS 4.0
High
Find Similar
Published Jun 18, 2026 1w ago
Last Modified Jun 22, 2026 1w ago

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.

CVSS Details

Base Score
8.3
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
18.2% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-125 Out-of-bounds Read Memory Safety

References 4

  • github.com https://github.com/libssh2/libssh2/commit/2dae3024897e1898d389835151f4e9606227721d
  • github.com https://github.com/libssh2/libssh2/pull/1705
  • github.com https://github.com/libssh2/libssh2/pull/1717
  • vulncheck.com https://www.vulncheck.com/advisories/libssh2-heap-buffer-over-read-via-sftp-symlink-in-sftp-c

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.