PatchTheCVECVE-2026-34840: OneUptime is an open-source monitoring and observability platform
CVE-2026-34840 is a high-severity flaw (CVSS 8.1) affecting oneuptime. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- High severity
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.1 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 82%) |
| CISA exploited list | No |
| Weakness | CWE-347 |
| Published | 2026-04-02 |
| Last modified | 2026-10-06 |
Last updated 2026-10-06 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-34840?
oneuptime: upgrade to 10.0.42. Exact commands for each OS are on this page.
Is CVE-2026-34840 being exploited?
CVE-2026-34840 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-34840 affect?
CVE-2026-34840 affects oneuptime. Severity is high (CVSS 8.1). 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. isSignatur
How urgent is CVE-2026-34840?
Priority 38/100. High severity; Public exploit reference
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