MCP server autoloads .env at import time
Summary
MCP server module that silently calls `dotenv.config()` at import time, reading secrets from the caller's CWD .env without declaring the capability. Any host running the MCP with a .env in the working directory leaks those values into the MCP process.
Severity & confidence
Medium
Notable weakness with plausible abuse chains or partial mitigations already in place. Track, and resolve as part of your normal hardening cadence.
Confirmed
Observed directly by Jiffy scanners or validated by multiple independent sources. Indicators are reliable enough to drive automated action.
Indicators
Observed patterns and artifacts associated with this entry. Each indicator can be copied into your detection stack or SIEM.
(?i)from\s+dotenv\s+import\s+load_dotenv.{0,120}load_dotenv\s*\(
Detection rule
A YARA-style pseudo-rule auto-generated from the indicators above. Useful as a starting point — adapt the syntax for your target detection platform.
rule jiffy_ti_2026_000054
{
meta:
source = "jiffy-intel"
severity = "medium"
description = "Auto-generated from Jiffy Intel indicators"
strings:
$content_pattern_0 = "(?i)from\\s+dotenv\\s+import\\s+load_dotenv.{0,120}load_dotenv\\s*\\("
condition:
$content_pattern_0
}Auto-generated from the indicators above. Adapt syntax for your detection stack before deploying.
Affected tools
| Tool | Versions | Status |
|---|---|---|
| Any MCP-capable agent | * | vulnerable |
Example artifacts
Sanitized examples of artifacts Jiffy has observed exhibiting this pattern. Publisher handles are redacted; version ranges and status reflect the most recent scan.
- config-loader-mcpMCP serverStill live
- env-helper-mcpMCP serverUnder review
How to remediate
- 01MCP servers should read config from an explicit path, not implicit CWD .env.
- 02Jiffy SDK enforces this.
Timeline & sources
Timeline
- First observedFeb 27, 20261 month ago
- Last updatedApr 22, 2026today
- PublishedMar 13, 20261 month ago
Sources
References
Scan for patterns like this
Point Jiffy at your GitHub org, IDE config, or a single artifact. Get a scored report in under a minute.
Start a free scan