CVE-2026-40194

low
Published 2026-04-10 · Modified 2026-05-08
CVSS v3
3.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS v2
VIR risk
3.7

Description

phpseclib has a variable-time HMAC comparison in SSH2::get_binary_packet() using != instead of hash_equals()

Predictions

Exploit likelihood
47%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-40194

vendor Authored 2026-05-27

Vendor advisory: security-advisories@github.com — https://github.com/phpseclib/phpseclib/security/advisories/GHSA-r854-jrxh-36qx

vendor Authored 2026-05-27

Vendor advisory: security-advisories@github.com — https://github.com/phpseclib/phpseclib/releases/tag/3.0.51

vendor Authored 2026-05-27

Vendor advisory: security-advisories@github.com — https://github.com/phpseclib/phpseclib/releases/tag/2.0.53

vendor Authored 2026-05-27

Vendor advisory: security-advisories@github.com — https://github.com/phpseclib/phpseclib/releases/tag/1.0.28

vendor Authored 2026-05-27

Vendor advisory: security-advisories@github.com — https://github.com/phpseclib/phpseclib/commit/ffe48b6b1b1af6963327f0a5330e3aa004a194ac

OS impact

OSVersionStatusFixed in
debian debianbookwormfixed2.0.42-1+deb12u4
debian debianbullseyeaffected
debian debianforkyfixed2.0.53-1
debian debiansidfixed2.0.53-1
debian debiantrixiefixed2.0.48-3+deb13u2

Package impact

EcosystemPackageVulnerableFixed
php Packagistphpseclib/phpseclib>=0.1.1,<1.0.28|>=3.0.0,<3.0.51|>=2.0.0,<2.0.53
php Packagistphpseclib/phpseclib>=0.1.1,<1.0.281.0.28
php Packagistphpseclib/phpseclib>=2.0.0,<2.0.532.0.53
php Packagistphpseclib/phpseclib>=3.0.0,<3.0.513.0.51
php COMPOSERphpseclib/phpseclib>= 0.1.1, < 1.0.281.0.28
php COMPOSERphpseclib/phpseclib>= 3.0.0, < 3.0.513.0.51
php COMPOSERphpseclib/phpseclib>= 2.0.0, < 2.0.532.0.53

Application impact

VendorProductVersionsFixed
phpseclibphpseclib{"endIncluding":"1.0.27"}

References

CWEs

CWE-208

Verify integrity in audit chain (admin only). AS-IS.