AI agent vulnerability · Langflow

CVE-2026-55423: Langflow: Logout button does not clear session

mediumCVSS 3.1 6.1GHSA-7hw8-6q6r-4276

Summary The logout button does not clear the session. The previous user stays logged in unless another user explicitly logs in. Details Not in auto login mode. Hosted on localhost. accesstokenlf remains present in both Local Storage and Cookies. refreshtokenlf remains present in Cookies.

Published Jun 19, 2026 · Updated Sep 24, 2026

Affected packages

langflow

Ecosystem: PyPI
Affected: < 1.7.0
Fixed in: 1.7.0
Check: pip show langflow

Advisory details

From the GitHub Advisory Database (CC BY 4.0).

Summary

The logout button does not clear the session. The previous user stays logged in unless another user explicitly logs in.

Details

Not in auto login mode. Hosted on localhost. access_token_lf remains present in both Local Storage and Cookies. refresh_token_lf remains present in Cookies.

Root cause: the /logout endpoint deleted the authentication cookies without matching the original httponly/samesite/secure/domain parameters, so the browser kept them; additionally the frontend did not clear the auth cookies on logout.

LANGFLOW_AUTO_LOGIN: "False"
LANGFLOW_SUPERUSER: <set>
LANGFLOW_SUPERUSER_PASSWORD: <set>
LANGFLOW_SECRET_KEY: <set>
LANGFLOW_NEW_USER_IS_ACTIVE: "False"
LANGFLOW_ENABLE_SUPERUSER_CLI: "False"

PoC

Click Logout. Hit refresh to return to previous screen.

Impact

Users on shared computers may falsely believe they have terminated their session.

Patches

Fixed in 1.7.0 (PRs #10527 and #10528). The logout endpoint now deletes the auth cookies using the same parameters they were created with, and the frontend clears the auth cookies on logout. Upgrade to 1.7.0 or later.

Credited to iann0036, Cristhianzl, AntonioABLima, andifilhohub, massif-01, cookesan.

References

How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology

More Langflow vulnerabilities

All Langflow entries