CVE-2026-30956
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOneUptime is a solution for monitoring and managing online services. Prior to 10.0.21, a low‑privileged user can bypass authorization and tenant isolation in OneUptime v10.0.20 and earlier by sending a forged is-multi-tenant-query header together with a controlled projectid header. Because the server trusts this client-supplied header, internal permission checks in BasePermission are skipped and tenant scoping is disabled. This allows attackers to access project data belonging to other tenants, read sensitive User fields via nested relations, leak plaintext resetPasswordToken, and reset the victim’s password and fully take over the account. This results in cross‑tenant data exposure and full account takeover. This vulnerability is fixed in 10.0.21.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOneUptime prior to 10.0.21 allows low-privileged users to bypass authorization by sending forged is-multi-tenant-query and projectid headers. The server incorrectly trusts these client-supplied headers, causing BasePermission checks to be skipped and tenant scoping to be disabled, enabling cross-tenant data access and account takeover via plaintext resetPasswordToken leakage.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 10.0.21CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed OneUptime versionCheck the version file or package.json in the OneUptime installation directory, or run: npm list oneuptime or cat package.json | grep versionAffected if The installed version is 10.0.20 or prior (< 10.0.21)
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Locate BasePermission implementationSearch the codebase for the BasePermission file/module that handles authorization checks, typically in a permissions or middleware directoryAffected if BasePermission exists and processes is-multi-tenant-query or projectid headers without server-side validation
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Inspect HTTP header handling logicReview the code that reads is-multi-tenant-query and projectid headers from incoming HTTP requests - look for direct trust of these client-supplied values in authorization logicAffected if The application directly uses these headers to determine tenant context without validating them against authenticated session data
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Check for sensitive field exposure in API responsesTest API endpoints that return user data by supplying manipulated tenant headers, specifically look for resetPasswordToken or other sensitive fields in responsesAffected if API responses include resetPasswordToken or other sensitive User fields when tenant headers are manipulated
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Review tenant isolation configurationExamine how tenant scoping is enforced in database queries - check if query filters include tenant validation that cannot be overridden by HTTP headersAffected if Tenant isolation can be bypassed by supplying custom HTTP headers, allowing cross-tenant data access
You are affected if OneUptime version is prior to 10.0.21 and the application processes is-multi-tenant-query/projectid headers from requests without server-side validation in the BasePermission layer.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped10.0.21
Upgrade OneUptime to version 10.0.21 or later. Review server-side header validation logic to ensure client-supplied headers cannot bypass permission checks.
OneUptime 10.0.21
- 1. Back up the current OneUptime installation and database before upgrading
- 2. Upgrade OneUptime to version 10.0.21 or later
- 3. Verify the upgrade was successful by checking the version number
- 4. Test that tenant isolation is working properly - verify that low-privileged users cannot access cross-tenant data
- 5. Confirm that the is-multi-tenant-query header is no longer trusted client-side and is validated server-side
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-30956 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-30956 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data