MediumVulnerability

CVE-2026-55946: Microsoft Copilot command injection allows unauthorized information disclosure

Source: NVD(opens in a new tab)
Identifier: CVE-2026-55946
Published: September 17, 2026
Record updated: October 9, 2026

Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.4%

Summary

CVE-2026-55946 is an improper neutralization of special elements used in a command ('command injection') flaw in Microsoft Copilot. An unauthorized attacker can exploit it over a network to disclose information.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

Details

Scores and exploitation

CVSS score: 6.1(medium)
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N
Attack vector: network
Attack complexity: high
Privileges required: none
User interaction: required
EPSS: 0.4%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 4, 2026.
Disclosure date: September 17, 2026

Weaknesses and techniques

Weakness (CWE): CWE-77
Attack pattern (CAPEC): CAPEC-88

Affected

Vendors: Microsoft

Classification

Attack type: Other
Attack sophistication: Moderate
AI component targeted: API
Impact: Confidentiality
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-55946

First tracked: September 17, 2026 at 08:07 PM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 85% (self-assessed)

Topics

Coding assistants

Summary

Mitigation

Topics

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