PYSEC-2026-2533 LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service)

Summary The LTI 1.1 validator stores OAuth nonces in a class-level dictionary that grows without bounds. Nonces are added before signature validation, so an attacker with knowledge of a valid consumer key can send repeated requests with unique nonces to gradually exhaust server memory, causing a...

CLEANSTART-2026-UZ41796 Security fixes for CVE-2026-42304, CVE-2026-44307, CVE-2026-48522, CVE-2026-48523, CVE-2026-48524, CVE-2026-48525, CVE-2026-48526, ghsa-2h4p-vjrc-8xpq, ghsa-grgv-6hw6-v9g4 applied in versions: 4.3.5-r0, 4.3.5-r1

Multiple security vulnerabilities affect the jupyterhub-k8s-hub package. These issues are resolved in later releases. See references for individual vulnerability details...

PYSEC-2026-1692 nbgrader's `frame-ancestors: self` grants all users access to formgrader

Impact Enabling frame-ancestors: 'self' grants any JupyterHub user the ability to extract formgrader content by sending malicious links to users with access to formgrader, at least when using the default JupyterHub configuration of enablesubdomains = False. 1915 disables a protection which would...

PYSEC-2026-1711 Globus `identity_provider` restriction ignored when used with `allow_all` in JupyterHub 5.0

Impact JupyterHub 5.0, when used with GlobusOAuthenticator, could be configured to allow all users from a particular institution only. The configuration for this would look like: python Require users to be using the "foo.horse" identity provider, often an institution or university...

PYSEC-2026-1480 Cross site scripting (XSS) in JupyterHub via Self-XSS leveraged by Cookie Tossing

Impact Affected configurations: - Single-origin JupyterHub deployments - JupyterHub deployments with user-controlled applications running on subdomains or peer subdomains of either the Hub or a single-user server. By tricking a user into visiting a malicious subdomain, the attacker can achieve an...

PYSEC-2026-1312 DockerSpawner allows any image by default

Impact Users of JupyterHub deployments running DockerSpawner starting with 0.11.0 without specifying DockerSpawner.allowedimages configuration allow users to launch any pullable image, instead of restricting to only the single configured image, as intended. Patches Upgrade to DockerSpawner 13...

Exploit for Cross-Site Request Forgery (CSRF) in Jupyter Jupyterhub

CVE-2026-40864 — JupyterHub XSRF bypass via cross-origin form...

CLEANSTART-2026-MJ28981 Security fixes for CVE-2026-42304, CVE-2026-44307, CVE-2026-48522, CVE-2026-48523, CVE-2026-48524, CVE-2026-48525, CVE-2026-48526, ghsa-2h4p-vjrc-8xpq, ghsa-grgv-6hw6-v9g4 applied in versions: 4.3.5-r0, 4.3.5-r1

Multiple security vulnerabilities affect the jupyterhub-k8s-hub package. These issues are resolved in later releases. See references for individual vulnerability details...

GHSA-M68R-V472-JGQ9 vulnerabilities

Vulnerabilities for packages: py3-jupyterhub...

CVE-2026-40864 vulnerabilities

Vulnerabilities for packages: py3-jupyterhub...

GHSA-M68R-V472-JGQ9 vulnerabilities

Vulnerabilities for packages: py3-jupyterhub...

CVE-2026-40864 vulnerabilities

Vulnerabilities for packages: py3-jupyterhub...

Linux Distros Unpatched Vulnerability : CVE-2026-40864

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0...

PYSEC-2026-2189

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...

DEBIAN-CVE-2026-40864

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...

CVE-2026-40864

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...

CVE-2026-40864

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...

UBUNTU-CVE-2026-40864

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...

CVE-2026-40864

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...

CVE-2026-40864 JupyterHub: Cross-origin form POSTs bypass XSRF

JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection updated in 4.1.0 inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affecte...