CVE-2026-58201
Lokka: Azure Resource Manager URL path validation issue
Lokka is a Model Context Protocol server for Microsoft 365, including Microsoft Graph and other services. Prior to 2.1.2, the Lokka-Microsoft tool in src/mcp/src/main.ts uses direct URL string concatenation to append the user-controlled path value to the management.azure.com base URL. A specially crafted path can alter URL authority parsing and cause an Azure Resource Manager bearer token to be sent to an unintended host. This issue is fixed in version 2.1.2.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Lokka: Azure Resource Manager URL path validation issue
Lokka is a Model Context Protocol server for Microsoft 365, including Microsoft Graph and other services. Prior to 2.1.2, the Lokka-Microsoft tool in src/mcp/src/main.ts uses direct URL string concatenation to append the user-controlled path value to the management.azure.com base URL. A specially crafted path can alter URL authority parsing and cause an Azure Resource Manager bearer token to be sent to an unintended host. This issue is fixed in version 2.1.2.
- Record
CVE-2026-58201- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-918
- Updated
- 2026-11-02
EUVDEUVD-2026-78934
Lokka is a Model Context Protocol server for Microsoft 365, including Microsoft Graph and other services. Prior to 2.1.2, the Lokka-Microsoft tool in src/mcp/src/main.ts uses direct URL string concatenation to append the user-controlled path value to the management.azure.com base URL. A specially crafted path can alter URL authority parsing and cause an Azure Resource Manager bearer token to be sent to an unintended host. This issue is fixed in version 2.1.2.
- Record
EUVD-2026-78934- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-g2gw-q38m-vjfc
Lokka: Azure Resource Manager URL path validation issue
Lokka versions prior to 2.1.2 constructed Azure Resource Manager request URLs using direct string concatenation with user-controlled path input. Specially crafted path values could alter URL authority parsing and cause Azure Resource Manager bearer tokens to be sent to an unintended host. Version 2.1.2 fixes the issue by validating Azure paths before token acquisition and constructing Azure Resource Manager URLs with the standard URL API while preserving the expected management.azure.com host.
Reported by 정해창 [email protected]
- Record
GHSA-g2gw-q38m-vjfc- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-918
- Updated
- 2026-11-02
NVD
Lokka is a Model Context Protocol server for Microsoft 365, including Microsoft Graph and other services. Prior to 2.1.2, the Lokka-Microsoft tool in src/mcp/src/main.ts uses direct URL string concatenation to append the user-controlled path value to the management.azure.com base URL. A specially crafted path can alter URL authority parsing and cause an Azure Resource Manager bearer token to be sent to an unintended host. This issue is fixed in version 2.1.2.
- Record
CVE-2026-58201- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-918
- Updated
- 2026-11-02
OSV
Lokka: Azure Resource Manager URL path validation issue
Lokka is a Model Context Protocol server for Microsoft 365, including Microsoft Graph and other services. Prior to 2.1.2, the Lokka-Microsoft tool in src/mcp/src/main.ts uses direct URL string concatenation to append the user-controlled path value to the management.azure.com base URL. A specially crafted path can alter URL authority parsing and cause an Azure Resource Manager bearer token to be sent to an unintended host. This issue is fixed in version 2.1.2.
- Record
CVE-2026-58201- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-918
- Updated
- 2026-11-02
OSVGHSA-g2gw-q38m-vjfc
Lokka: Azure Resource Manager URL path validation issue
Lokka versions prior to 2.1.2 constructed Azure Resource Manager request URLs using direct string concatenation with user-controlled path input. Specially crafted path values could alter URL authority parsing and cause Azure Resource Manager bearer tokens to be sent to an unintended host. Version 2.1.2 fixes the issue by validating Azure paths before token acquisition and constructing Azure Resource Manager URLs with the standard URL API while preserving the expected management.azure.com host.
Reported by 정해창 [email protected]
- Record
GHSA-g2gw-q38m-vjfc- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-918
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@merill/lokkanpm |
before 2.1.2 | 2.1.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-58201 is a high vulnerability (CVSS 8.7) in Merill Lokka, published June 19, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.48%, the 41st percentile. Fixed in @merill/lokka 2.1.2.
References
github.com/merill/lokka/security/advisories/GHSA-g2gw-q38m-vjfc
nvd.nist.gov/vuln/detail/CVE-2026-58201