GHSA-7hw8-6q6r-4276 CVE-2026-55423 PYSEC-2026-222

Langflow: Logout button does not clear session

Medium PyPI

Severity: 6.1 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 0.22%; Chance of exploitation in the next 30 days. Higher than 12.77% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-613 Insufficient Session Expiration
Fix: 1.7.0; Upgrade langflow to this version or later

Description

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

PyPI

Package	Vulnerable	Fixed in
langflow	`< 1.7.0`	`1.7.0`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

langflow PyPI → `1.7.0`

pip

pip install --upgrade "langflow>=1.7.0"

poetry

poetry add "langflow>=1.7.0"

uv

uv add "langflow>=1.7.0"

Severity breakdown

CVSS 3.1 6.1

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack vector: Physical
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Weakness

CWE-613: Insufficient Session Expiration

According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization."

How to prevent it

Implementation: Set sessions/credentials expiration date.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2026-55423

Packages

github.com/langflow-ai/langflow

Timeline

Jun 19, 2026 Published
Oct 25, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-qrpv-q767-xqq2 Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow	High Known exploited	Also affects langflow
GHSA-vwmf-pq79-vjvx Unauthenticated Remote Code Execution in Langflow via Public Flow Build Endpoint	Critical Known exploited	Also affects langflow
GHSA-g22f-v6f7-2hrh Langflow affected by Remote Code Execution via validate_code() exec()	High Known exploited	Also affects langflow
GHSA-577h-p2hh-v4mv Langflow CORS misconfiguration enables Account Takeover and RCE	Critical Known exploited	Also affects langflow
GHSA-rvqx-wpfh-mfx7 Langflow Unauth RCE	Critical Known exploited	Also affects langflow
GHSA-j8f7-x8jm-wmm4 Langflow: SSRF in URL-taking components (protection disabled by default / warn-only, not applied to RSS, SearXNG, Web Search, Home Assistant, Glean, Docling)	Medium	Also affects langflow
GHSA-4f6c-2vvp-gw82 Langflow: IP Spoofing Bypass via `X-Forwarded-For` Allowing Remote Configuration Write	High	Also affects langflow
GHSA-4hmc-cfm3-w43c Langflow has Authenticated Cross-Project File Disclosure via Unscoped MCP Resource Handlers	High	Also affects langflow

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