SB2026050499 - Multiple vulnerabilities in Flowise

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Main Vulnerability Database SB2026050499

SB2026050499 - Multiple vulnerabilities in Flowise

Published: May 4, 2026

Security Bulletin ID SB2026050499
CSH Severity
High
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Path traversal (CVE-ID: N/A)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to write arbitrary files.

The vulnerability exists due to improper input validation in the addBase64FilesToStorage function when processing chat flow creation requests containing base64 file data. A remote attacker can supply a crafted chatflow id to write arbitrary files.


2) Path traversal (CVE-ID: N/A)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to improper input validation in the streamStorageFile function when handling file download requests. A remote attacker can provide crafted chatflowId and chatId values to disclose sensitive information.

The affected download APIs are listed in WHITELIST_URLS, allowing exploitation without authentication.


3) Improper access control (CVE-ID: N/A)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to improper access control in the Custom MCP feature when handling requests to load custom MCP server configurations. A remote attacker can send a specially crafted request to execute arbitrary code.

By default, installations may operate without authentication unless credentials are explicitly configured.


Remediation

Install update from vendor's website.

References