MCP server depends on minimist with prototype-pollution CVE
Summary
Node-based MCP servers that indirectly pull a vulnerable minimist version through an old yargs. Prototype pollution affects the MCP's own runtime behavior.
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)"minimist"\s*:\s*"[\^~]?(?:0|1\.[0-1])\.
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_000056
{
meta:
source = "jiffy-intel"
severity = "medium"
description = "Auto-generated from Jiffy Intel indicators"
strings:
$content_pattern_0 = "(?i)\"minimist\"\\s*:\\s*\"[\\^~]?(?:0|1\\.[0-1])\\."
condition:
$content_pattern_0
}Auto-generated from the indicators above. Adapt syntax for your detection stack before deploying.
Affected tools
| Tool | Versions | Status |
|---|---|---|
| MCP servers (Node) | minimist<1.2.6 | 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.
- arg-parse-mcpMCP serverStill live
- cli-wrapper-mcpMCP serverStill live
How to remediate
Bump transitive dependency; pin minimist>=1.2.6.
Timeline & sources
Timeline
- First observedMar 5, 20261 month ago
- Last updatedApr 24, 2026today
- PublishedMar 17, 20261 month ago
Sources
References
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