CVE-2026-107366: CWE-639 Authorization Bypass Through User-Controlled Key in IBM Langflow OSS
Description
IBM Langflow OSS versions 1.0.0 through 1.12.4 have an authorization bypass vulnerability (CWE-639) in three message endpoints that lack ownership verification. Authenticated users can exploit this to bulk-delete other users' messages, overwrite message content with malicious prompts, or hijack conversation sessions by reassigning session IDs. The vulnerability has a high severity with a CVSS score of 8.3.
CVSS v3.1
Score 8.3high
Affected software
IBM
Langflow OSS
pkg:github/ibm/langflow_osscpe:2.3:a:ibm:langflow_oss:1.0.0:*:*:*:*:*:*:*cpe:2.3:a:ibm:langflow_oss:1.12.4:*:*:*:*:*:*:*Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-107366 affects IBM Langflow OSS versions 1.0.0 through 1.12.4. The vulnerability arises because three message endpoints do not verify ownership, allowing any authenticated user to perform unauthorized actions on other users' messages. These actions include bulk deletion of messages, injecting malicious content by overwriting message data, and hijacking conversation sessions by changing session IDs. This constitutes an authorization bypass (CWE-639) with significant confidentiality and integrity impacts.
Potential Impact
Exploitation allows an authenticated user to delete messages belonging to other users, inject malicious prompts by overwriting message content, and hijack entire conversation sessions by reassigning session IDs. This leads to high confidentiality and integrity impact and a low availability impact as per the CVSS vector.
Mitigation Recommendations
No official patch or remediation information is provided. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to authenticated users carefully and monitor for suspicious activity related to message endpoints.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- ibm
- Date Reserved
- 2026-10-07T20:49:16.611Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad6b05e2cdf04f656aa8fd0
Added to database: 10/20/2026, 00:05:50 UTC
Last enriched: 10/20/2026, 00:18:19 UTC
Last updated: 10/20/2026, 00:19:57 UTC
Views: 5
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