Vulnerability · Published Mar 6, 2026 · Assigned by GitHub_M
CVE-2026-28787OneUptime has WebAuthn 2FA bypass: server accepts client-supplied challenge instead of server-stored value, allowing credential replay
High 8.2
In plain English
A high-severity improper authentication in oneuptime from OneUptime. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @oneuptime/common | no fix listed | GHSA-gjjc-pcwp-c74m |
Affected products (as reported)
Weakness: CWE-287, CWE-294 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
References
- https://github.com/OneUptime/oneuptime/security/advisories/GHSA-gjjc-pcwp-c74m x_refsource_CONFIRM