CVEvulnerability

CVE-2026-28787

9.0 CRITICAL Published 2026-03-06 Modified 2026-06-17 Official page ↗
Status
Analyzed
Published
2026-03-06
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.2 HIGH — CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
CVSS 3.1 ([email protected])
9.0 CRITICAL — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Weaknesses
CWE-287, CWE-294

Description

OneUptime is a solution for monitoring and managing online services. In version 10.0.11 and prior, the WebAuthn authentication implementation does not store the challenge on the server side. Instead, the challenge is returned to the client and accepted back from the client request body during verification. This violates the WebAuthn specification (W3C Web Authentication Level 2, §13.4.3) and allows an attacker who has obtained a valid WebAuthn assertion (e.g., via XSS, MitM, or log exposure) to replay it indefinitely, completely bypassing the second-factor authentication. No known patches are available.

Affected configurations

• hackerbay oneuptime (<= 10.0.11)

Related

Weakness · CWE (2)

  • CWE-287 Improper Authentication weakness
  • CWE-294 Authentication Bypass by Capture-replay weakness

References