CVE-2026-27203

8.3 HIGH
Published: February 21, 2026 Modified: February 23, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
8.3 / 10.0
EPSS (Exploit Probability)
0.0%
14th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)