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CVE-2026-40934PYSEC-2026-69GHSA-5MRQ-X3X5-8V8F

jupyter-server authentication cookies remain valid after password reset due to static cookie secret

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 2.18.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: total

Summary

Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the secret used to sign authentication cookies is persisted to a static file at ~/.local/share/jupyter/runtime/jupyter_cookie_secret and is never rotated when a user changes their password. After a password reset and server restart, any previously issued authentication cookie remains cryptographically valid because the signing key has not changed. An attacker who has captured a session cookie through any means retains full authenticated access to the server regardless of subsequent password changes. This affects deployments using password-based authentication, particularly shared or public-facing servers where credential rotation is expected to revoke existing sessions. This issue has been fixed in version 2.18.0.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: total

  3. Record last updated

Affected versions

  • jupyter-server jupyter_server

    fixed in 2.18.0

  • jupyter-serverPyPI

    fixed in 2.18.0

References 1

GitHub · jupyter-server/jupyter_server