eBay API MCP Server is an open source local MCP server providing AI assistants with comprehensive access to eBay's Sell APIs. All versions are vulnerable to Environment Variable Injection through the updateEnvFile function. The ebay_set_user_tokens tool allows updating the .env file with new tokens. The updateEnvFile function in src/auth/oauth.ts blindly appends or replaces values without validating them for newlines or quotes. This allows an attacker to inject arbitrary environment variables into the configuration file. An attacker can inject arbitrary environment variables into the .env file. This could lead to configuration overwrites, Denial of Service, and potential RCE. There was no fix for this issue at the time of publication.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-97rm-xj73-33jh eBay API MCP Server Affected by Environment Variable Injection
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 20 Feb 2026 23:45:00 +0000

Type Values Removed Values Added
Description eBay API MCP Server is an open source local MCP server providing AI assistants with comprehensive access to eBay's Sell APIs. All versions are vulnerable to Environment Variable Injection through the updateEnvFile function. The ebay_set_user_tokens tool allows updating the .env file with new tokens. The updateEnvFile function in src/auth/oauth.ts blindly appends or replaces values without validating them for newlines or quotes. This allows an attacker to inject arbitrary environment variables into the configuration file. An attacker can inject arbitrary environment variables into the .env file. This could lead to configuration overwrites, Denial of Service, and potential RCE. There was no fix for this issue at the time of publication.
Title eBay API MCP Server Affected by Environment Variable Injection
Weaknesses CWE-15
CWE-74
References
Metrics cvssV3_1

{'score': 8.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-20T23:30:46.134Z

Reserved: 2026-02-18T19:47:02.155Z

Link: CVE-2026-27203

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-21T00:16:17.463

Modified: 2026-02-21T00:16:17.463

Link: CVE-2026-27203

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses