Out-of-bounds Read Affecting libssh2-devel package, versions <1.11.0-150200.9.8.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.37% (30th percentile)

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  • Snyk IDSNYK-SLES155-LIBSSH2DEVEL-18591935
  • published8 Aug 2026
  • disclosed7 Aug 2026

Introduced: 7 Aug 2026

NewCVE-2026-66033  (opens in a new tab)
CWE-125  (opens in a new tab)
CWE-191  (opens in a new tab)

How to fix?

Upgrade SLES:15.5 libssh2-devel to version 1.11.0-150200.9.8.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libssh2-devel package and not the libssh2-devel package as distributed by SLES. See How to fix? for SLES:15.5 relevant fixed versions and status.

libssh2 through 1.11.1, fixed in commit a2ed82d, contains a pre-authentication integer underflow vulnerability in the ssh2_cipher_crypt() function in src/openssl.c that allows a malicious SSH server to crash any connecting client by negotiating AES-GCM ciphers during handshake. Attackers can exploit the underflow in the expression computing blocksize minus aadlen minus authentication tag length to trigger an out-of-bounds read and a memcpy call with a near-SIZE_MAX length argument, causing immediate process crash before any authentication occurs.

CVSS Base Scores

version 3.1