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CVE-2026-28787

OneUptime has WebAuthn 2FA bypass: server accepts client-supplied challenge instead of server-stored value, allowing credential replay

Published: Mar 6, 2026Updated: Mar 6, 2026 Sources: CVE List NVD GHSACWE-287
NVD MITRE
8.2CVSSHIGH
EPSS Score
0.3%
Top 80.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

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 Vector Breakdown

AV:NAC:HPR:LUI:NS:CC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-287CWE-294

Affected Products

oneuptimeOneUptime
Mixed
Enterprise Software / itsm-monitoring
@oneuptime/commonnpmOSS Libraries
oneuptimecommercialEnterprise Softwareaka oneuptime.com
npmpackage-ecosystemOSS Libraries

Attack Graph

Products CVE Techniques Tactics

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Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

MITRE ATT&CK

3 techniques
Defense Evasion
Initial Access
View detailed technique mapping

References

https://github.com/OneUptime/oneuptime/security/advisories/GHSA-gjjc-pcwp-c74m
github.com
https://nvd.nist.gov/vuln/detail/CVE-2026-28787
nvd.nist.gov
https://github.com/OneUptime/oneuptime
github.com

Timeline

Published
Mar 6, 2026
Last Updated
Mar 6, 2026

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