XSS in Hackerbay Oneuptime
CVE-2026-32308
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (20.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Hackerbay Oneuptime
- Oneuptime — versions < 10.0.23
Weakness classification (CWE)
References
- github.com/OneUptime/oneuptime/security/advisories/GHSA-wvh5-6vjm-23qh (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-32308?
- CVE-2026-32308 is a high-severity vulnerability in Hackerbay Oneuptime, classified under Cross-site Scripting. CVSS score: 7.6/10. Published 2026-03-13.
- How severe is CVE-2026-32308?
- High severity. CVSS v3 base score is 7.6 out of 10.