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TI-2026-21129 Aliases CVE-2026-26136GHSA-4mgh-xjf3-7388

Microsoft Copilot Information Disclosure Vulnerability

Priority LOW 36CWE-77Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from Microsoft.

Summary

Improper neutralization of special elements used in a command ('command injection') in Microsoft Copilot allows an unauthorized attacker to disclose information over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00692 53rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft Copilot-—No fix listedCNA
  • Microsoft Copilot VendorMicrosoft Affected - Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:copilot:-:*:*:*:*:*:*:*not specified by NVDVulnerableMicrosoft
  • cpe:2.3:a:microsoft:copilot:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Information Disclosure
Exploited
No
Publicly disclosed
No
Exploitability
—

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-26136
  2. 2026-10-03 Alias added: GHSA-4mgh-xjf3-7388

References

Patch 1

  • TI-2026-31033 M365 Copilot Information Disclosure Vulnerability CVSS 3.1HIGH 7.5
  • TI-2026-33267 Microsoft M365 Copilot Remote Code Execution Vulnerability CVSS 3.1HIGH 8.8
  • TI-2026-19585 Microsoft Copilot Information Disclosure Vulnerability CVSS 3.1HIGH 8.8
  • TI-2026-39842 Outlook Copilot Tampering Vulnerability CVSS 3.1HIGH 7.1
  • TI-2026-40352 Microsoft Copilot Information Disclosure Vulnerability CVSS 3.1MEDIUM 6.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences