365 CopilotApplication · Microsoft

CVE-2026-41090

CRITICAL · 9.3 CVSS v3.1 Published 2026-05-22
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges

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 · unedited
Improper neutralization of special elements used in a command ('command injection') in Microsoft Copilot allows an unauthorized attacker to perform tampering over a network.

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 confidence

Command injection vulnerability in Microsoft Copilot allows unauthorized attackers to inject and execute arbitrary commands on the underlying system by improper neutralization of special elements in user input, enabling network-based tampering attacks.

MitigationApply Microsoft security updates for Copilot when available; implement strict input validation and sanitization for all user-supplied data processed by Copilot; restrict Copilot's system-level permissions to minimize impact of potential command injection.

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
365 CopilotApplication
Affected:all versions

CVSS 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
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Microsoft 365 Copilot is enabled in your tenant
    Sign in to Microsoft 365 admin center, navigate to Setup > Apps and services, or run Get-M365CopilotLicense in Microsoft Graph PowerShell to list licensed users with Copilot access
    Affected if Copilot licenses are assigned and the service shows as enabled in your tenant
  2. Identify network-exposed Copilot interfaces
    Review your network perimeter configuration for any public-facing endpoints that provide Copilot access, including conditional access policies that allow remote access to Microsoft 365 Copilot services
    Affected if Copilot is accessible from untrusted networks without multi-factor authentication or VPN requirements
  3. Review sign-in logs for suspicious command patterns
    In Microsoft 365 admin center, go to Defender > Audit > Sign-in logs, or use Search-UnifiedAuditLog with Copilot-related activities. Filter for anomalous IP addresses or unusual request patterns
    Affected if Audit logs show login attempts from unexpected locations or suspicious input patterns targeting Copilot prompts
  4. Check conditional access policies for Copilot
    Navigate to Microsoft Entra ID > Protection > Conditional Access and review policies targeting Copilot services. Verify that policies require compliant devices, trusted locations, or strong authentication
    Affected if Conditional access policies are absent or allow broad access to Copilot without strict authentication controls

Your environment is affected if Microsoft 365 Copilot is enabled and accessible, since all versions of Copilot contain this command injection vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Microsoft security updates for Copilot when available; implement strict input validation and sanitization for all user-supplied data processed by Copilot; restrict Copilot's system-level permissions to minimize impact of potential command injection.

Fix this in 365 Copilot Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-41090 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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