CVE-2026-58201: Lokka: Azure Resource Manager URL path validation issue

Severity: high (CVSS 8.7 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-15 · updated 2026-09-30
Weakness: CWE-918

Description

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.

Affected products

merill lokka: before 2.1.2

References

https://github.com/merill/lokka/commit/babead878f44cc2face2f8ee55d8b706e420947e
https://github.com/merill/lokka/pull/47
https://github.com/merill/lokka/security/advisories/GHSA-g2gw-q38m-vjfc

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