What is CVE-2026-34758?

CVE-2026-34758 is a critical-severity vulnerability in Hackerbay Oneuptime, classified under Missing Authentication for Critical Function. CVSS score: 9.1/10. Published 2026-04-02.

How severe is CVE-2026-34758?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Auth bypass in Hackerbay Oneuptime

CVE-2026-34758

OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, unauthenticated access to Notification test and Phone Number management endpoints allows SMS/Call/Email/WhatsApp abuse and phone number purchase. This issue has been patched in version 10.0.42.

Vulnerability class: Broken Authentication

Published 2026-04-02 · last modified 2026-07-24.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.005 (40.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.001

Affected products

Hackerbay Oneuptime
Oneuptime — versions < 10.0.42

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

github.com/OneUptime/oneuptime/security/advisories/GHSA-q253-6wcm-h8hp (Exploit, Mitigation, Vendor Advisory)
github.com/OneUptime/oneuptime/commit/9adbd04538714740506708d6fa610e433be4d2a4 (Patch)
github.com/OneUptime/oneuptime/releases/tag/10.0.42 (Release Notes)

Frequently asked questions

What is CVE-2026-34758?: CVE-2026-34758 is a critical-severity vulnerability in Hackerbay Oneuptime, classified under Missing Authentication for Critical Function. CVSS score: 9.1/10. Published 2026-04-02.
How severe is CVE-2026-34758?: Critical severity. CVSS v3 base score is 9.1 out of 10.