CVE-2026-34046 Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check
Authenticated users can read, modify, or delete other users' AI workflows and exposed API keys due to missing ownership checks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-34046?
CVE-2026-34046 is a high-severity missing authorization vulnerability in Langflow Langflow, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Which versions are affected by CVE-2026-34046?
6 open source packages ship an affected version, including langflow and langflow-base. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
langflow PyPI | All versions | 1.5.1 |
langflow PyPI | All versions | 1.5.1 |
langflow PyPI | All versions | 1.5.1 |
langflow-base PyPI | All versions | 0.5.1 |
langflow-base PyPI | All versions | 0.5.1 |
langflow-base PyPI | All versions | 0.5.1 |
Products include Langflow Langflow, Langflow Langflow-Base.
How do I fix CVE-2026-34046?
Upgrade langflow to 1.5.1 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-34046 being exploited?
There is no known exploitation of CVE-2026-34046 in the wild and no public exploit code.
Other vulnerabilities in Langflow Langflow
Sources
Also known as GHSA-8c4j-f57c-35cf, PYSEC-2026-2567, PYSEC-2026-2570.