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CVE-2026-40934

CVE-2026-40934 · jupyter-server authentication cookies remain valid after password reset due to static cookie secret

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.6 · High · EPSS 0.4% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • jupyter_server

    Versions
    • < 2.18.0: Affected

    No fix published

  • jupyter-server Debian:12

    Versions
    • 1.23.3-1
    • 1.23.3-2
    • 2.14.0-1
    • 2.14.2-1
    • 2.14.2-2
    • 2.14.2-3
    • 2.14.2-4
    • 2.14.2-5
    • 2.15.0-1
    • 2.17.0-1
    • 2.20.0-1
    • 2.20.0-2
    • 2.20.0-3
    • 2.9.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • jupyter-server Debian:13

    Versions
    • 2.15.0-1
    • 2.17.0-1
    • 2.20.0-1
    • 2.20.0-2
    • 2.20.0-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • jupyter-server Debian:14

    Versions
    • 2.15.0-1
    • 2.17.0-1
    Affected ranges
    • ECOSYSTEM: < 2.20.0-1

    Update to 2.20.0-1

  • jupyter-server PyPI

    Versions
    • 0.0.0
    • 0.0.1
    • 0.0.2
    • 0.0.3
    • 0.0.4
    • 0.0.5
    • 0.1.0
    • 0.1.1
    • 0.2.0
    • 0.2.1
    • 0.3.0
    • 1.0.0
    • 1.0.0rc0
    • 1.0.0rc1
    • 1.0.0rc10
    • 1.0.0rc11
    • 1.0.0rc12
    • 1.0.0rc13
    • 1.0.0rc14
    • 1.0.0rc15
    • 1.0.0rc16
    • 1.0.0rc2
    • 1.0.0rc3
    • 1.0.0rc4
    • 1.0.0rc5
    • 1.0.0rc6
    • 1.0.0rc7
    • 1.0.0rc8
    • 1.0.0rc9
    • 1.0.1
    • 1.0.10
    • 1.0.11
    • 1.0.2
    • 1.0.3
    • 1.0.4
    • 1.0.5
    • 1.0.6
    • 1.0.7
    • 1.0.8
    • 1.0.9
    • 1.1.0
    • 1.1.1
    • 1.1.2
    • 1.1.3
    • 1.1.4
    • 1.10.0
    • 1.10.1
    • 1.10.2
    • 1.11.0
    • 1.11.1
    • 1.11.2
    • 1.12.0
    • 1.12.1
    • 1.13.0
    • 1.13.1
    • 1.13.2
    • 1.13.3
    • 1.13.4
    • 1.13.5
    • 1.15.0
    • 1.15.1
    • 1.15.2
    • 1.15.3
    • 1.15.4
    • 1.15.5
    • 1.15.6
    • 1.16.0
    • 1.17.0
    • 1.17.1
    • 1.18.0
    • 1.18.1
    • 1.19.0
    • 1.19.1
    • 1.2.0
    • 1.2.1
    • 1.2.2
    • 1.2.3
    • 1.21.0
    • 1.23.0
    • 1.23.1
    • 1.23.2
    • 1.23.3
    • 1.23.4
    • 1.23.5
    • 1.23.6
    • 1.24.0
    • 1.3.0
    • 1.4.0
    • 1.4.1
    • 1.5.0
    • 1.5.1
    • 1.6.0
    • 1.6.1
    • 1.6.2
    • 1.6.3
    • 1.6.4
    • 1.7.0
    • 1.7.0a1
    • 1.7.0a2
    • 1.8.0
    • 1.9.0
    • 2.0.0
    • 2.0.0a0
    • 2.0.0a1
    • 2.0.0a2
    • 2.0.0b0
    • 2.0.0b1
    • 2.0.0rc0
    • 2.0.0rc1
    • 2.0.0rc2
    • 2.0.0rc3
    • 2.0.0rc4
    • 2.0.0rc5
    • 2.0.0rc6
    • 2.0.0rc7
    • 2.0.0rc8
    • 2.0.1
    • 2.0.2
    • 2.0.3
    • 2.0.4
    • 2.0.5
    • 2.0.6
    • 2.0.7
    • 2.1.0
    • 2.10.0
    • 2.10.1
    • 2.11.0
    • 2.11.1
    • 2.11.2
    • 2.12.0
    • 2.12.1
    • 2.12.2
    • 2.12.3
    • 2.12.4
    • 2.12.5
    • 2.13.0
    • 2.14.0
    • 2.14.1
    • 2.14.2
    • 2.15.0
    • 2.16.0
    • 2.17.0
    • 2.2.0
    • 2.2.1
    • 2.3.0
    • 2.4.0
    • 2.5.0
    • 2.6.0
    • 2.7.0
    • 2.7.1
    • 2.7.2
    • 2.7.3
    • 2.8.0
    • 2.9.0
    • 2.9.1
    Affected ranges
    • ECOSYSTEM: < 2.18.0

    Update to 2.18.0

  • jupyter-server Ubuntu:22.04:LTS

    Versions
    • 1.2.2-1
    • 1.13.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • jupyter-server Ubuntu:24.04:LTS

    Versions
    • 1.23.3-1
    • 1.23.3-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • jupyter-server Ubuntu:25.10

    Versions
    • 2.14.2-5
    • 2.15.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • jupyter-server Ubuntu:26.10

    Versions
    • 2.17.0-1
    • 2.20.0-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • jupyter-server Ubuntu:26.04:LTS

    Versions
    • 2.15.0-1
    • 2.17.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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