CVE-2026-28787

CRITICAL EPSS 19.3%
Published Mar 6, 20263mo ago · Modified Mar 10, 20263mo ago
9.0 CVSS 3.1
Critical
Find Similar
Published Mar 6, 2026 3mo ago
Last Modified Mar 10, 2026 3mo ago

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.

CVSS Details

Base Score
9.0
Exploitability
2.2
Impact
6.0
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Changed
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
19.3% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 2

CWE-287 Improper Authentication Authentication
CWE-294

Affected Products 1

VendorProductVersionRange
hackerbayoneuptime* ≤10.0.11

References 1

  • github.com https://github.com/OneUptime/oneuptime/security/advisories/GHSA-gjjc-pcwp-c74m
    ExploitVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.