CVE-2021-40818

9.8 criticalEPSS 1.5%

Critical (9.8) in glewlwyd sso server project glewlwyd sso server. EPSS 1.5% chance of exploitation in the next 30 days.

scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration.

Severity

9.8 critical

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

EPSS: 1.5% chance of exploitation in the next 30 days; higher than 74% of CVEs (scores of 2026-10-31)
CWE: CWE-120
Published: 2021-09-08
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19