Jiffy Intel — Threat intelligence for AI artifacts

Summary

MCP server points its auth flow at a third-party hostname that was abandoned by its original owner and re-registered by an attacker. Users completing the auth flow hand tokens to the attacker directly.

Severity & confidence

Severity

Critical

Active exploitation in the wild, high blast radius, or direct data exfiltration vector. Treat as an urgent remediation target; quarantine affected artifacts immediately.

Confidence

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.

https?://(?:auth|login|sso)\.(?:[a-z0-9-]+\.)+(?:fly\.dev|vercel\.app|pages\.dev)

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.

YARA-style pseudo-rule

rule jiffy_ti_2026_000053
{
    meta:
        source = "jiffy-intel"
        severity = "critical"
        description = "Auto-generated from Jiffy Intel indicators"
    strings:
    $endpoint_0 = "https?://(?:auth|login|sso)\\.(?:[a-z0-9-]+\\.)+(?:fly\\.dev|vercel\\.app|pages\\.dev)"
    condition:
        $endpoint_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.

legacy-saas-mcpMCP server
Removed
Source
MCP Registry
Versions
0.3.0
First observed
Mar 17, 2026
Last observed
Apr 12, 2026
old-service-mcpMCP server
Under review
Source
MCP Registry
First observed
Mar 21, 2026

How to remediate

01Audit MCP auth redirect hostnames against a known-good allowlist.
02Ephemeral PaaS hosts for auth flows are a red flag.

Timeline & sources

Timeline

First observedMar 17, 20261 month ago
Last updatedApr 26, 2026today
PublishedMar 27, 202621 days ago

Sources

curated

References

blog.jiffylabs.aiJiffy Research

Jiffy Research — MCP Security Field Guide

https://blog.jiffylabs.ai/posts/mcp-security-a-security-teams-field-guide

attack.mitre.org

MITRE ATT&CK T1195 — Supply Chain Compromise

https://attack.mitre.org/techniques/T1195/

Related intel

Other entries of type Compromised Mcp, or the most recent published entries if no same-type matches exist.

Compromised McpLow

MCP server registers global tool names that shadow Jiffy primitives

MCP server that claims the tool name `scan` or `analyze` — names already used by Jiffy's first-party MCP. Collisions are resolved non-deterministically by the client, allowing the malicious server's tool to receive calls intended for Jiffy.

Jiffy IntelApr 28

Compromised McpCritical

Custom GPT Action schema includes an undocumented "admin" path

Custom GPT's OpenAPI schema defines a `/admin` path that the model can call, not mentioned in the GPT description. The path accepts arbitrary shell commands and runs them on the Action backend.