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OpenAdvisories
High · 7.6 CVE-2026-40934 EUVD-2026-27513GHSA-5mrq-x3x5-8v8fPYSEC-2026-69

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

Published May 5, 2026 · Updated May 7, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
jupyter-server jupyter_server < 2.18.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 jupyter-server 2.20.0-1 —
Debian 13 jupyter-server No fix yet —
Debian 12 jupyter-server No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 jupyter-server No fix yet —
Ubuntu 26.04 LTS jupyter-server No fix yet —
Ubuntu 25.10 jupyter-server No fix yet —
Ubuntu 24.04 LTS jupyter-server No fix yet —
Ubuntu 22.04 LTS jupyter-server No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed python-jupyter-server 2.18.1-1.1 openSUSE-SU-2026:10710-1
ReleasePackageFixed inAdvisory
Alpine v3.24 jupyter-server 2.18.2-r0 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI jupyter-server < 2.18.0 2.18.0 GHSA-5mrq-x3x5-8v8f

Advisories 1

References