QwikSec

Security Database

CVE

CWE

Training

CVE Database
/

CVE-2026-40194

Back to search

CVE-2026-40194

Published: Apr 10, 2026

Modified: May 8, 2026

PUBLISHED

CVSS v3.1

3.7

LOW

Description

phpseclib is a PHP secure communications library. Starting in 0.1.1 and prior to 3.0.51, 2.0.53, and 1.0.28, phpseclib\Net\SSH2::get_binary_packet() uses PHP's != operator to compare a received SSH packet HMAC against the locally computed HMAC. != on equal-length binary strings in PHP uses memcmp(), which short-circuits on the first differing byte. This is a real variable-time comparison (CWE-208), proven by scaling benchmarks. This vulnerability is fixed in 3.0.51, 2.0.53, and 1.0.28.

VendorProductVersions

phpseclib

phpseclib

affected
>= 0.1.1, < 1.0.28
affected
>= 2.0.0, < 2.0.53
affected
>= 3.0.0, < 3.0.51

Weaknesses (CWE)

CWE-208

CVSS v3.1 Details

CVSS v3.1 Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

References

Security Training

Train your team to recognize and prevent security threats with our comprehensive security awareness program.

Start Training

Vulnerability Scanning

Discover vulnerabilities in your applications and infrastructure before attackers do.

Scan Now