CVE-2026-32308
OneUptime: Stored XSS via Mermaid Diagram Rendering (securityLevel: "loose")
CVSS Score
7.6
EPSS Score
0.0%
EPSS Percentile
0th
OneUptime is a solution for monitoring and managing online services. Prior to 10.0.23, the Markdown viewer component renders Mermaid diagrams with securityLevel: "loose" and injects the SVG output via innerHTML. This configuration explicitly allows interactive event bindings in Mermaid diagrams, enabling XSS through Mermaid's click directive which can execute arbitrary JavaScript. Any field that renders markdown (incident descriptions, status page announcements, monitor notes) is vulnerable. This vulnerability is fixed in 10.0.23.
| CWE | CWE-79 |
| Vendor | oneuptime |
| Product | oneuptime |
| Published | Mar 12, 2026 |
| Last Updated | Mar 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None
Affected Versions
OneUptime / oneuptime
< 10.0.23