---
id: CVE-2026-34840
title: OneUptime is an open-source monitoring and observability platform
summary: >-
  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. isSigna…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-347
vendor: hackerbay
product: oneuptime
affected:
  - oneuptime < 10.0.42
patched:
  - oneuptime 10.0.42
published: '2026-04-02'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T22:10:00.247'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-34840'
references:
  - url: >-
      https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1
    label: security-advisories@github.com
  - url: 'https://github.com/OneUptime/oneuptime/releases/tag/10.0.42'
    label: security-advisories@github.com
  - url: >-
      https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00343
epssPercentile: 0.25661
ingestedAt: '2026-10-06T22:23:15.913Z'
---

## Overview

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.

## Affected

- `oneuptime < 10.0.42`

## Remediation

Upgrade past the affected range:

- `oneuptime 10.0.42`