Is CVE-2026-27203 actively exploited?

No active exploitation of CVE-2026-27203 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-27203 be exploited remotely?

Yes. CVE-2026-27203 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-27203?

CVE-2026-27203 has a CVSS score of 8.3 (HIGH) and an EPSS exploitation probability of 0.05%.

HOME VULNERABILITIESCVE-2026-27203

HIGH

CVE-2026-27203

CWE-15Published: February 21, 2026· Updated: Feb 23, 2026

8.3

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:12.8th

Official 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.

NVD Source

Technical Analysis

CVE-2026-27203 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.3.