What is CVE-2026-34840?

CVE-2026-34840 is a high-severity vulnerability in Oneuptime, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.1/10. Published 2026-04-02.

How severe is CVE-2026-34840?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Oneuptime

CVE-2026-34840

OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime's SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatu…

EPSS: 0.000 (12.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

Affected products

Oneuptime — versions < 10.0.42

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g (x_refsource_CONFIRM)
https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1 (x_refsource_MISC)
https://github.com/OneUptime/oneuptime/releases/tag/10.0.42 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-34840?: CVE-2026-34840 is a high-severity vulnerability in Oneuptime, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.1/10. Published 2026-04-02.
How severe is CVE-2026-34840?: High severity. CVSS v3 base score is 8.1 out of 10.