CVE-2026-41269Public exploitNetwork attack vector

Authenticated web-shell upload via mutable MIME allowlist

Published Apr 23, 2026 · Updated Apr 23, 2026

Unrestricted file upload in Flowise before 3.1.0 allows remote authenticated users to store JavaScript files through Chatflow attachments. The createAttachment path trusts the Chatflow allowedUploadFileTypes setting, so application/javascript can be added and a .js attachment accepted. Low-privileged authenticated access is required; the stored file gains command execution only if an administrator triggers it or another flaw executes it.

CVSS severity7.1
High
EPSS probability0.47%
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 3.1.0 allows remote authenticated users to store JavaScript files through Chatflow attachments. The createAttachment path trusts the Chatflow allowedUploadFileTypes setting, so application/javascript can be added and a .js attachment accepted. Low-privileged authenticated access is required; the stored file gains command execution only if an administrator triggers it or another flaw executes it.

The record

CVE
CVE-2026-41269
Published
Apr 23, 2026
Updated
Apr 23, 2026
Vendor
FlowiseAI
Product
Flowise
Classifications
CWE-434, T1505.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=< 3.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FlowiseAI · Flowiseversion=< 3.1.0

Published CVSS scores

7.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Server Software Component: Web Shell

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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