Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2026-34840

8.1 · HIGH

OneUptime is an open-source monitoring and observability platform.

Published Apr 2, 2026CWE-347EPSS 0.34%

Overview

CVE-2026-34840 is a high-severity vulnerability. It was published on April 2, 2026 and has a CVSS 3.1 base score of 8.1 (HIGH).

This vulnerability has a CVSS 3.1 base score of 8.1, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.

Technical description

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. isSignatureValid() verifies the first <Signature> element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

GitHubgithub.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1GitHubgithub.com/OneUptime/oneuptime/releases/tag/10.0.42GitHubgithub.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g

How CyberStrike helps

Frequently asked questions

What is CVE-2026-34840?

CVE-2026-34840 is a high-severity vulnerability. It was published on April 2, 2026 and has a CVSS 3.1 base score of 8.1 (HIGH).

How severe is CVE-2026-34840?

This vulnerability has a CVSS 3.1 base score of 8.1, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2026-34840?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-34840?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-34840 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related HIGH CVEs from 2026

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999