CVE-2026-55423: Langflow Logout Button Does Not Clear Vulnerability

MODERATE
Advisory Identifier: GHSA-7hw8-6q6r-4276
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CVSS 6.1
CWE-613
Published
Advisory Summary

CVE-2026-55423 is a MODERATE (CVSS 6.1) logout button does not clear vulnerability (CWE-613: Insufficient Session Expiration) affecting Langflow libraries in the PyPI ecosystem. The issue involves logout button does not clear session. Remediation is available by upgrading affected packages to version 1.7.0.

CVE-2026-55423 at a Glance

CVE Identifier CVE-2026-55423
GHSA Identifier GHSA-7hw8-6q6r-4276
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-613: Insufficient Session Expiration
Affected Product Langflow
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N).

Attack Vector Physical (AV:P)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-55423

To remediate this vulnerability, upgrade all affected Langflow dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

langflow fixed: 1.7.0 
pip install langflow>=1.7.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show langflow

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-55423, inspect your installed packages using pip:

pip show langflow

Analyze the terminal output to locate any version of Langflow in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.7.0), your application is affected.

Note: The pip show langflow command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-613: Insufficient Session Expiration, where according to wasc, "insufficient session expiration is when a web site permits an attacker to reuse old session credentials or session ids for authorization.". In Langflow, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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**.

CVE-2026-55423 Affected Langflow Versions

1 component(s)
Fixed Versions:
1.7.0
Product / Package Ecosystem Affected Versions Fixed Version
langflow
pypi/langflow
PyPI
< 1.7.0
1.7.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/langflow-ai/langflow/security/advisories/GHSA-7hw8-6q6r-4276
NVD — CVE-2026-55423 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-55423
Langflow Source Repository REPOSITORY
https://github.com/langflow-ai/langflow/pull/10527
Langflow Source Repository REPOSITORY
https://github.com/langflow-ai/langflow/pull/10528
Langflow Source Repository REPOSITORY
https://github.com/langflow-ai/langflow
Langflow Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-222.yaml

Frequently Asked Questions

What is CVE-2026-55423?
CVE-2026-55423 is a security vulnerability in Langflow involving Logout button does not clear session under CWE-613: Insufficient Session Expiration.
Which Langflow versions are affected?
Affected versions include releases prior to 1.7.0 across affected packages: langflow.
What version fixes CVE-2026-55423?
Upgrading to 1.7.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is langflow affected?
Yes, langflow is affected in releases prior to 1.7.0. Upgrade your dependency to 1.7.0 or later.
What is the CVSS score of CVE-2026-55423?
CVE-2026-55423 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-55423?
CVE-2026-55423 is classified under 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 can I check PyPI dependencies for CVE-2026-55423?
Run the dependency tree command: 'pip show langflow'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7hw8-6q6r-4276",
  "modified" : "2026-09-24T14:57:10Z",
  "published" : "2026-06-19T21:17:01Z",
  "aliases" : [ "CVE-2026-55423" ],
  "summary" : "Langflow: Logout button does not clear session",
  "details" : "### Summary\nThe logout button does not clear the session. The previous user stays logged in unless another user explicitly logs in.\n\n### Details\nNot 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.\n\n**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.\n\n```\nLANGFLOW_AUTO_LOGIN: \"False\"\nLANGFLOW_SUPERUSER: <set>\nLANGFLOW_SUPERUSER_PASSWORD: <set>\nLANGFLOW_SECRET_KEY: <set>\nLANGFLOW_NEW_USER_IS_ACTIVE: \"False\"\nLANGFLOW_ENABLE_SUPERUSER_CLI: \"False\"\n```\n\n### PoC\nClick Logout. Hit refresh to return to previous screen.\n\n### Impact\nUsers on shared computers may falsely believe they have terminated their session.\n\n### Patches\nFixed 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**.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "langflow"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.7.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/langflow-ai/langflow/security/advisories/GHSA-7hw8-6q6r-4276"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-55423"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/langflow-ai/langflow/pull/10527"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/langflow-ai/langflow/pull/10528"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/langflow-ai/langflow"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-222.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-613" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T21:17:01Z",
    "nvd_published_at" : "2026-06-23T17:17:08Z"
  }
}