VulnerabilityModified
CVE-2026-40194
This vulnerability is fixed in 3.0.51, 2.0.53, and 1.0.28.
LOW 3.7EPSS 0.36%
Does this matter?
Lower severity and a low EPSS score (0.36%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 3.7 LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 0.36% probability · 30th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-208
- Affected
- phpseclib/phpseclib
- Source
- security-advisories@github.com
References
- https://github.com/phpseclib/phpseclib/commit/ffe48b6b1b1af6963327f0a5330e3aa004a194acPatch
- https://github.com/phpseclib/phpseclib/releases/tag/1.0.28Release Notes
- https://github.com/phpseclib/phpseclib/releases/tag/2.0.53Release Notes
- https://github.com/phpseclib/phpseclib/releases/tag/3.0.51Release Notes
- https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qxVendor Advisory
- https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qxVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.