VDB-398849 · CVE-2026-9186 · GCVE-0-2026-9186

IBM Langflow up to 1.11.2 MCP Configuration .cursor/mcp.json X-Forwarded-For access control

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.4	$5k-$25k	0.41-

Summaryinfo

A vulnerability has been found in IBM Langflow up to 1.11.2 and classified as problematic. Affected by this vulnerability is an unknown functionality of the file .cursor/mcp.json of the component MCP Configuration Handler. The manipulation of the argument X-Forwarded-For leads to access control. This vulnerability is traded as CVE-2026-9186. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in IBM Langflow up to 1.11.2 and classified as problematic. This issue affects an unknown part of the file .cursor/mcp.json of the component MCP Configuration Handler. The manipulation of the argument X-Forwarded-For with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is integrity. The summary by CVE is:

IBM Langflow OSS 1.0.0 through 1.11.2 allows remote authenticated attackers to bypass localhost-only MCP configuration installation by spoofing X-Forwarded-For: 127.0.0.1 header, enabling arbitrary writes to IDE config files (~/.cursor/mcp.json, etc.).

The advisory is shared at ibm.com. The identification of this vulnerability is CVE-2026-9186 since 05/21/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/04/2026). MITRE ATT&CK project uses the attack technique T1068 for this issue.

By approaching the search of inurl:.cursor/mcp.json it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

Name

Langflow

Version

License

commercial

Website

Vendor: https://www.ibm.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.4

VulDB Base Score: 4.3
VulDB Temp Score: 4.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (ibm): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Google Hack: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/21/2026 CVE reserved
09/04/2026 +106 days Advisory disclosed
09/04/2026 +0 days VulDB entry created
09/04/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: ibm.com

Advisory: ibm.com
Status: Confirmed

CVE: CVE-2026-9186 (🔒)
GCVE (CVE): GCVE-0-2026-9186
GCVE (VulDB): GCVE-100-398849

Entryinfo

Created: 09/04/2026 17:11
Changes: 09/04/2026 17:11 (64)
Complete: 🔍
Cache ID: 216::103