CVE-2025-71334: Flowise has arbitrary file access due to missing chat flow id validation

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 4.4%, percentile 91: FIRST’s model estimates a 4.4% chance of exploitation activity in the next 30 days, higher than 91% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes flowise (npm) >= 2.2.8, < 3.0.6, fixed in 3.0.6. Check your lockfile, including transitive dependencies.

What it is

Flowise before 3.0.6 contains an arbitrary file access vulnerability due to missing validation that the chatflowId and chatId parameters are UUIDs or numbers in file handling operations. By supplying a path-traversal value (e.g., '../../../../../tmp') as the chatflow id, an unauthenticated attacker can use the /api/v1/chatflows endpoint (via addBase64FilesToStorage) to write arbitrary files, and the /api/v1/get-upload-file and /api/v1/openai-assistants-file/download endpoints (via streamStorageFile) to read arbitrary files. Arbitrary file write may lead to remote code execution.

From the GitHub advisory

Summary

Missing chat flow id validation allows an attacker to access arbitrary file.

Details

Commit https://github.com/FlowiseAI/Flowise/commit/8bd3de41533de78e4ef6c980e5704a1f9cb7ae6f and https://github.com/FlowiseAI/Flowise/commit/c2b830f279e454e8b758da441016b2234f220ac7 added check for filename when handling file upload operations to prevent path traversal, and additional validation of chatflowId and chatId from route /api/v1/attachments. In some cases, however, chatflowId and chatId are not validated to ensure they are UUIDs or numbers, which may lead to security issues.

Case 1

Weakness type: CWE-73, CWE-22.

Product: flowise (npm) · Assigned by: VulnCheck · Published: 2026-06-25

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-11-04): 4.36% probability of exploitation activity in the next 30 days; percentile 91.

Timeline

• 2025-09-15 — GitHub-reviewed advisory GHSA-q67q-549q-p849 published (critical)
• 2026-06-25 — CVE record published by VulnCheck
• 2026-10-29 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. GitHub Security Advisory (GHSA-q67q-549q-p849) github.com
2. Vendor advisory (github.com) github.com
3. Vendor advisory (github.com) github.com

Vulnerability records

1. GitHub Advisory GHSA-q67q-549q-p849 github.com
2. CVE.org record CVE-2025-71334 cve.org
3. NVD entry CVE-2025-71334 nvd.nist.gov

Other references from the CVE record and advisory

1. VulnCheck Advisory: Flowise - Arbitrary File Access via Missing Chat Flow ID Validation vulncheck.com

Critical npm advisories · Today’s Security Digest