CVE-2026-30821Public exploitNetwork attack vector

Unauthenticated file upload via MIME spoofing

Published Mar 7, 2026 · Updated Mar 7, 2026

Unrestricted file upload in Flowise before 3.0.13 allows remote attackers to persist arbitrary files through an unauthenticated API. The attachments route trusts multipart Content-Type metadata and passes files to addArrayFilesToStorage without checking extensions or magic bytes. Exploitation requires an upload-enabled chatflow; code execution or stored XSS additionally requires a retrieval or hosting path that processes the stored file.

CVSS severity8.2
High
EPSS probability14.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in Flowise before 3.0.13 allows remote attackers to persist arbitrary files through an unauthenticated API. The attachments route trusts multipart Content-Type metadata and passes files to addArrayFilesToStorage without checking extensions or magic bytes. Exploitation requires an upload-enabled chatflow; code execution or stored XSS additionally requires a retrieval or hosting path that processes the stored file.

The record

CVE
CVE-2026-30821
Published
Mar 7, 2026
Updated
Mar 7, 2026
Vendor
FlowiseAI
Product
Flowise
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.0.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FlowiseAI · Flowiseversion=< 3.0.13

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.2GitHubCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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