Microsoft 365 Copilot command injection

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.8$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Microsoft 365 Copilot. This impacts an unknown function. The manipulation leads to command injection. This vulnerability is uniquely identified as CVE-2026-42827. The attack is possible to be carried out remotely. No exploit exists. This product is a managed service. It is not possible for users to maintain vulnerability countermeasures themselves.

Detailsinfo

A vulnerability was found in Microsoft 365 Copilot (affected version not known) and classified as critical. This issue affects some unknown functionality. The manipulation with an unknown input leads to a command injection vulnerability. Using CWE to declare the problem leads to CWE-77. The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. Impacted is confidentiality. The summary by CVE is:

Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to disclose information over a network.

The advisory is shared at msrc.microsoft.com. The identification of this vulnerability is CVE-2026-42827 since 04/30/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/23/2026). MITRE ATT&CK project uses the attack technique T1202 for this issue.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

Name

License

Managed Service

  • yes

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (microsoft): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Command injection
CWE: CWE-77 / CWE-74 / CWE-707
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Status: 🔍

0-Day Time: 🔒

Timelineinfo

04/30/2026 CVE reserved
05/23/2026 +23 days Advisory disclosed
05/23/2026 +0 days VulDB entry created
05/23/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-42827 (🔒)
GCVE (CVE): GCVE-0-2026-42827
GCVE (VulDB): GCVE-100-365297

Entryinfo

Created: 05/23/2026 07:56
Changes: 05/23/2026 07:56 (61)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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