Langflow: Logout button does not clear session
Medium6.1CVE-2026-55423 · Published Jun 19, 2026 · updated Sep 24, 2026
### 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**.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| langflow PyPI | < 1.7.0 | 1.7.0 |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-613
- Also known as
- CVE-2026-55423, PYSEC-2026-222
- github.com/langflow-ai/langflow/security/advisories/GHSA-7hw8-6q6r-4276
- nvd.nist.gov/vuln/detail/CVE-2026-55423
- github.com/langflow-ai/langflow/pull/10527
- github.com/langflow-ai/langflow/pull/10528
- github.com/langflow-ai/langflow
- github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-222.yaml
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| Jun 19 | Langflow: BaseFileComponent-based nodes arbitrary file read with RCE exploit Critical9.6Jun 19 | Critical9.6 | 1.9.2 |
| Jun 19 | Langflow: Unauthenticated DoS through multipart form boundary file uploadHigh7.5Jun 19 | High7.5 | 1.0.19 |
| Jun 19 | Langflow: insecure direct object referenceHigh8.4Jun 19 | High8.4 | 1.9.1 |
| Jun 17 | Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leakCritical9.3Jun 17 | Critical9.3 | 1.9.1 |
| Jun 16 | Langflow: Unauthenticated Shareable Playground arbitrary local or S3 file readMedium6.1Jun 16 | Medium6.1 | 1.10.0 |
| Jun 16 | Langflow: Unauthenticated RCE in Shareable PlaygroundsCritical9.6Jun 16 | Critical9.6 | 1.9.2 |