Vulnerability details
CVE-2026-34046
Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check
Official description
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.5.1, the `_read_flow` helper in `src/backend/base/langflow/api/v1/flows.py` branched on the `AUTO_LOGIN` setting to decide whether to filter by `user_id`. When `AUTO_LOGIN` was `False` (i.e., authentication was enabled), neither branch enforced an ownership check — the query returned any flow matching the given UUID regardless of who owned it. This allowed any authenticated user to read any other user's flow, including embedded plaintext API keys; modify the logic of another user's AI agents, and/or delete flows belonging to other users. The vulnerability was introduced by the conditional logic that was meant to accommodate public/example flows (those with `user_id = NULL`) under auto-login mode, but inadvertently left the authenticated path without an ownership filter. The fix in version 1.5.1 removes the `AUTO_LOGIN` conditional entirely and unconditionally scopes the query to the requesting user.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 8.7High | 4.0 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| langflow-ai | langflow | < 1.5.1 | CVEProject cvelistV5 (CNA) |
| langflow-ai | langflow-base | < 0.5.1 | CVEProject cvelistV5 (CNA) |
References and advisories
2- https://github.com/langflow-ai/langflow/security/advisories/GHSA-8c4j-f57c-35cf x_refsource_CONFIRM
- https://github.com/langflow-ai/langflow/pull/8956 x_refsource_MISC
Details
- Published
- 2026-03-27
- Last updated
- 2026-11-04
- State
- Published
- Assigner (CNA)
- GitHub_M
Exploit prediction (EPSS)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-639Authorization Bypass Through User-Controlled Key
- CWE-862Missing Authorization