CVE-2026-40194

LOW EPSS 25.2%
Published Apr 10, 20262mo ago · Modified Jun 17, 20261w ago
3.7 CVSS 3.1
Low
Find Similar
Published Apr 10, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
3.7
Exploitability
2.2
Impact
1.4
Vector string
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

Threat Intelligence

EPSS Exploit Probability
25.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-208

Affected Products 3

VendorProductVersionRange
phpseclibphpseclib* ≤1.0.27
phpseclibphpseclib*≥2.0.0  –  <2.0.53
phpseclibphpseclib*≥3.0.0  –  <3.0.51

References 5

  • github.com https://github.com/phpseclib/phpseclib/commit/ffe48b6b1b1af6963327f0a5330e3aa004a194ac
    Patch
  • github.com https://github.com/phpseclib/phpseclib/releases/tag/1.0.28
    Release Notes
  • github.com https://github.com/phpseclib/phpseclib/releases/tag/2.0.53
    Release Notes
  • github.com https://github.com/phpseclib/phpseclib/releases/tag/3.0.51
    Release Notes
  • github.com https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qx
    Vendor Advisory

Remediation

  • github.com https://github.com/phpseclib/phpseclib/commit/ffe48b6b1b1af6963327f0a5330e3aa004a194ac
    Patch