CVE-2026-58057: exploitation status and patch state

CVE-2026-58057 · CVSS 5.0 MEDIUM · EPSS 1%

Flowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using a case-sensitive comparison, so on Windows, where environment names are case-insensitive, supplying 'node_options' bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP node can thereby inject NODE_OPTIONS --require and execute arbitrary code in the Flowise server context.

Is CVE-2026-58057 exploited?

• Not in the CISA KEV catalog.
• EPSS puts exploitation in the next 30 days at 1%.
• Public exploit code: proof of concept.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2026-58057

• AI Fuzzing Turns One Dump Into Mass PoCs (2026-07-03)

Primary sources

• NVD record
• Exploit-DB 52623

What this record does not say

• No affected package data.
• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-08-12.