Out-of-bounds Read Affecting libssh2 package, versions <1.11.1-1ubuntu0.26.04.2


Severity

Recommended
0.0
medium
0
10

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.65% (49th percentile)

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  • Snyk IDSNYK-UBUNTU2604-LIBSSH2-17398224
  • published1 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 Ubuntu:26.04 libssh2 to version 1.11.1-1ubuntu0.26.04.2 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 Ubuntu. See How to fix? for Ubuntu:26.04 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