Microsoft 365 Copilots Business Chat server-side request forgery

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 (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
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.
7.7$5k-$25k0.00

Summaryinfo

A vulnerability described as critical has been identified in Microsoft 365 Copilots Business Chat. This vulnerability affects unknown code. Such manipulation leads to server-side request forgery. This vulnerability is referenced as CVE-2026-26137. It is possible to launch the attack remotely. No exploit is available. This product is a managed service, indicating that users are not permitted to maintain vulnerability countermeasures themselves.

Detailsinfo

A vulnerability was found in Microsoft 365 Copilots Business Chat (unknown version) and classified as critical. Affected by this issue is an unknown code block. The manipulation with an unknown input leads to a server-side request forgery vulnerability. Using CWE to declare the problem leads to CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Server-side request forgery (ssrf) in Microsoft Exchange allows an authorized attacker to elevate privileges over a network.

The advisory is shared for download at msrc.microsoft.com. This vulnerability is handled as CVE-2026-26137 since 02/11/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 03/28/2026).

This product is available as a managed service. Users are not able to maintain vulnerability countermeasures themselves.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

License

Managed Service

  • yes

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.7
VulDB Meta Temp Score: 7.7

VulDB Base Score: 5.5
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.9
CNA Vector (microsoft): 🔒

CVSSv2info

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

Exploitinginfo

Class: Server-side request forgery
CWE: CWE-918
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

02/11/2026 CVE reserved
03/20/2026 +37 days Advisory disclosed
03/20/2026 +0 days VulDB entry created
03/28/2026 +7 days VulDB entry last update

Sourcesinfo

Vendor: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2026-26137 (🔒)
GCVE (CVE): GCVE-0-2026-26137
GCVE (VulDB): GCVE-100-351860

Entryinfo

Created: 03/20/2026 07:43
Updated: 03/28/2026 00:35
Changes: 03/20/2026 07:43 (62), 03/24/2026 08:57 (5), 03/28/2026 00:35 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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