Summary
Langflow: Logout button does not clear session
Full technical description
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.
CVE-2026-55423 has a CVSS score of 6.1 (Medium). The vector is requires physical access, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.7.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
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.
Frequently Asked Questions
- What is CVE-2026-55423? CVE-2026-55423 is a medium-severity security vulnerability in langflow (pip), affecting versions < 1.7.0. It is fixed in 1.7.1.
- How severe is CVE-2026-55423? CVE-2026-55423 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of langflow are affected by CVE-2026-55423? langflow (pip) versions < 1.7.0 is affected.
- Is there a fix for CVE-2026-55423? Yes. CVE-2026-55423 is fixed in 1.7.1. Upgrade to this version or later.
- Is CVE-2026-55423 exploitable, and should I be worried? Whether CVE-2026-55423 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-55423 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-55423? Upgrade
langflowto 1.7.1 or later.