CVE-2026-40934

Description

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.

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Produits concernés

• jupyter-server jupyter_server
• Jupyter jupyter server

Scores CVSS

Faiblesses (CWE)

• CWE-613

Références

• https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-5mrq-x3x5-8v8f ExploitMitigationVendor Advisory

Ailleurs

• NVD
• CVE.org
• CIRCL Vulnerability-Lookup
• CERT-FR
• GitHub Advisories