CVE-2026-4064
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 · uneditedMissing authorization checks on multiple gRPC service endpoints in PowerShell Universal before 2026.1.4 allows an authenticated user with any valid token to bypass role-based access controls and perform privileged operations — including reading sensitive data, creating or deleting resources, and disrupting service operations — via crafted gRPC requests.
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 · moderate confidencePowerShell Universal versions before 2026.1.4 contain missing authorization checks on multiple gRPC service endpoints, allowing any authenticated user with a valid token to bypass role-based access control (RBAC) restrictions and perform privileged operations including reading sensitive data, creating or deleting resources, and disrupting service operations through crafted gRPC requests.
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< 2026.1.4CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
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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Check PowerShell Universal installed versionRetrieve the installed version of PowerShell Universal (e.g., via Get-ItemProperty on the installation directory, package manager, or running 'Get-PSUVersion' if the module is loaded)Affected if The installed version is earlier than 2026.1.4 (e.g., 2026.1.3, 2025.x, or older)
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Verify gRPC service is enabledInspect the PowerShell Universal configuration (typically in appsettings.json or the admin dashboard) to determine if gRPC endpoints are enabled and exposedAffected if gRPC service endpoints are enabled and accessible on the server
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Confirm authentication token usageReview the authentication configuration to determine if gRPC endpoints accept bearer tokens or session tokens for API accessAffected if gRPC endpoints accept valid authentication tokens (which can then bypass RBAC checks)
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Inspect RBAC role assignmentsExamine the configured roles and role assignments in PowerShell Universal (via the admin portal or configuration files) to identify which users have authenticated accessAffected if Any authenticated users exist with valid tokens, regardless of their assigned role (since RBAC can be bypassed on gRPC)
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Assess network exposure of gRPC endpointsDetermine if gRPC endpoints are listening on external or internal network interfaces, and whether they are accessible beyond localhostAffected if gRPC endpoints are reachable from network locations beyond trusted administrators
You are affected if PowerShell Universal version is earlier than 2026.1.4 AND gRPC endpoints are enabled and accessible to authenticated users.
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 · scoped2026.1.4
Upgrade PowerShell Universal to version 2026.1.4 or later to receive the patched authorization checks on gRPC endpoints. Until then, consider restricting network access to gRPC endpoints or implementing additional authentication layers.
2026.1.4
- Upgrade PowerShell Universal to version 2026.1.4 or later to address the missing authorization vulnerability on gRPC service endpoints
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-4064 — 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-2026-4064 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
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