Out-of-bounds Read Affecting libssh2 package, versions <1.11.1-r7


Severity

Recommended
0.0
medium
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.65% (49th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-CHAINGUARDLATEST-LIBSSH2-17973029
  • published15 Jul 2026
  • disclosed18 Jun 2026

Introduced: 18 Jun 2026

CVE-2025-15661  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade Chainguard libssh2 to version 1.11.1-r7 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libssh2 package and not the libssh2 package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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 Base Scores

version 3.1