GHSA-7grx-3xcx-2xv5 CVE-2026-33484 PYSEC-2026-80
langflow has Unauthenticated IDOR on Image Downloads
- Severity
- 7.5 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 5.94%
- Chance of exploitation in the next 30 days. Higher than 93.27% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-284 Improper Access Control
- CWE-639 Authorization Bypass Through User-Controlled Key
- CWE-862 Missing Authorization
- Fix
1.9.0- Upgrade langflow to this version or later
Description
Summary
The /api/v1/files/images/{flow_id}/{file_name} endpoint serves image files without any authentication or ownership check. Any unauthenticated request with a known flow_id and file_name returns the image with HTTP 200.
Details
src/backend/base/langflow/api/v1/files.py:138-164 — download_image takes flow_id: UUID as a bare path parameter with no Depends(get_flow) or CurrentActiveUser. All other file routes (download_file, upload_file, list_files, delete_file) use Depends(get_flow) which enforces both authentication and ownership. There is no global auth middleware on /api/v1; protection is per-endpoint only.
PoC
curl -v "http://localhost:7860/api/v1/files/images/<flow_uuid>/<filename.png>"
# Returns HTTP 200 with image bytes, no auth header required
Impact
Unauthenticated cross-tenant data leak. In a multi-tenant deployment, any attacker who can discover or guess a flow_id (UUIDs can be leaked through other API responses) can download any user's uploaded images without credentials.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| langflow | >= 1.0.0, < 1.9.0 |
1.9.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
langflow PyPI → 1.9.0
- pip
pip install --upgrade "langflow>=1.9.0"- poetry
poetry add "langflow>=1.9.0"- uv
uv add "langflow>=1.9.0"
Severity breakdown
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Weakness
CWE-284: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How to prevent it
- Architecture and Design, Operation: Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
CWE-639: Authorization Bypass Through User-Controlled Key
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
How to prevent it
- Architecture and Design: For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
- Architecture and Design, Implementation: Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
- Architecture and Design: Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
CWE-862: Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
How to prevent it
- Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
- System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-qrpv-q767-xqq2 Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow | High Known exploited | Also affects langflow |
| GHSA-vwmf-pq79-vjvx Unauthenticated Remote Code Execution in Langflow via Public Flow Build Endpoint | Critical Known exploited | Also affects langflow |
| GHSA-g22f-v6f7-2hrh Langflow affected by Remote Code Execution via validate_code() exec() | High Known exploited | Also affects langflow |
| GHSA-577h-p2hh-v4mv Langflow CORS misconfiguration enables Account Takeover and RCE | Critical Known exploited | Also affects langflow |
| GHSA-rvqx-wpfh-mfx7 Langflow Unauth RCE | Critical Known exploited | Also affects langflow |
| GHSA-j8f7-x8jm-wmm4 Langflow: SSRF in URL-taking components (protection disabled by default / warn-only, not applied to RSS, SearXNG, Web Search, Home Assistant, Glean, Docling) | Medium | Also affects langflow |
| GHSA-4f6c-2vvp-gw82 Langflow: IP Spoofing Bypass via `X-Forwarded-For` Allowing Remote Configuration Write | High | Also affects langflow |
| GHSA-4hmc-cfm3-w43c Langflow has Authenticated Cross-Project File Disclosure via Unscoped MCP Resource Handlers | High | Also affects langflow |
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