CVE-2026-67338

JupyterLab before 4.5.9 contains a stored cross-site scripting vulnerability in the Extension Manager that fails to validate URI protocols in package metadata URLs. Attackers can publish malicious PyPI packages with javascript: URLs in project metadata that execute arbitrary JavaScript in the...

CVE-2026-67338

CVE-2026-67338 affects JupyterLab prior to 4.5.9. A stored cross-site scripting vulnerability resides in the Extension Manager where URI protocols in package metadata URLs are not validated. This allows an attacker to publish malicious PyPI packages with javascript: URLs in project metadata, enab...

CVE-2026-67338

JupyterLab before 4.5.9 contains a stored cross-site scripting vulnerability in the Extension Manager that fails to validate URI protocols in package metadata URLs. Attackers can publish malicious PyPI packages with javascript: URLs in project metadata that execute arbitrary JavaScript in the...

CVE-2026-67338 JupyterLab before 4.5.9 Stored XSS via Extension Manager

JupyterLab before 4.5.9 contains a stored cross-site scripting vulnerability in the Extension Manager that fails to validate URI protocols in package metadata URLs. Attackers can publish malicious PyPI packages with javascript: URLs in project metadata that execute arbitrary JavaScript in the...

EUVD-2026-51849

JupyterLab before 4.5.9 contains a stored cross-site scripting vulnerability in the Extension Manager that fails to validate URI protocols in package metadata URLs. Attackers can publish malicious PyPI packages with javascript: URLs in project metadata that execute arbitrary JavaScript in the...

GHSA-PPPJ-HQ3G-57PJ JupyterLab: Cross-site scripting (XSS) via crafted settings file (`overrides.json`)

JupyterLab 4.5+ allows notebook settings to be shared and applied through an overrides.json file using the Import button in the Settings Editor. Certain notebook display settings were not properly validated before being applied. As a result, a crafted settings file could contain hidden instructio...

GHSA-89VP-JRXV-24W8 JupyterLab: PyPI extension blocklist package-name canonicalization bypass

JupyterLab's PyPI extension manager enforces blockedextensionsuris by comparing the requested install name to blocklist entries with a custom string normalization that is weaker than PyPI package-name canonicalization. An authenticated user can request a PyPI-equivalent spelling such as...

GHSA-WHVH-WF3X-G77J JupyterLab: Allowlist/blocklist check in `PyPIExtensionManager.install()` not enforced for direct callers (missing `await`)

The extension allowlist/blocklist check inside PyPIExtensionManager.install was not enforced due to a missing await. For purposes of JupyterLab this was a secondary defense-in-depth check: install was intended to enforce the allowlist/blocklist itself for any future uses and users calling this...

PYSEC-2026-2540 jupyterlab-git extension: Stored XSS leading to RCE

Overview Amazon Web Services AWS Security has identified a stored cross-site scripting XSS issue in the jupyterlab-git JupyterLab extension that can lead to remote code execution RCE. The issue exists in the PlainTextDiff.ts component, where the createHeader method passes Git filenames directly t...

PYSEC-2026-2539 jupyterlab-git excluded_paths Case-Sensitivity Bypass Allows Reading Excluded Directories

Summary jupyterlab-git 0.53.0 latest, 2026-04-30 uses fnmatch.fnmatchcase in GitHandler.prepare jupyterlabgit/handlers.py:91 to enforce the admin-configured excludedpaths security control. Because fnmatchcase is unconditionally case-sensitive, an authenticated user on a case-insensitive filesyste...

PYSEC-2026-2541 jupyterlab-git extension: Stored XSS leading to RCE

Overview Amazon Web Services AWS Security has identified a stored cross-site scripting XSS issue in the jupyterlab-git JupyterLab extension that can lead to remote code execution RCE. The issue exists in the PlainTextDiff.ts component, where the createHeader method passes Git filenames directly t...

PYSEC-2026-2681 JupyterLab's command linker attributes in HTML enable one-click command execution from untrusted content

JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with ...

PYSEC-2026-2537 JupyterLab's command linker attributes in HTML enable one-click command execution from untrusted content

JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with ...

PYSEC-2026-2534 JupyterLab vulnerable to potential authentication and CSRF tokens leak

Impact Users of JupyterLab who click on a malicious link may get their Authorization and XSRFToken tokens exposed to a third party when running an older jupyter-server version. Patches JupyterLab 4.1.0b2, 4.0.11, and 3.6.7 were patched. Workarounds No workaround has been identified, however users...

PYSEC-2026-2535 JupyterLab vulnerable to SXSS in Markdown Preview

Impact The vulnerability depends on user interaction by opening a malicious notebook with Markdown cells, or Markdown file using JupyterLab preview feature. A malicious user can access any data that the attacked user has access to as well as perform arbitrary requests acting as the attacked user...

Arbitrary Command Execution

GitHub CLI is vulnerable to Arbitrary Command Execution. The vulnerability is due to insufficient validation of JupyterLab URLs returned by a Codespace, where attacker-controlled non-loopback URLs such as vscode:// are passed to VS Code, allowing malicious Codespaces to execute arbitrary commands...

CVE-2026-54528

A flaw was found in JupyterLab Git, a Git extension for JupyterLab. This vulnerability allows an authenticated user on a case-insensitive filesystem to bypass administrator-configured excluded paths by varying the case of the URL path segment. This bypass enables the user to read file content, vi...

DEBIAN-CVE-2026-59831

GitHub CLI gh is GitHub’s official command line tool. From 2.10.0 through 2.95.0, connecting to a malicious Codespace with gh codespace jupyter can allow command execution because the command opens a JupyterLab URL supplied by a process inside the Codespace without validating that it is a loopbac...

CVE-2026-59831

GitHub CLI gh is GitHub’s official command line tool. From 2.10.0 through 2.95.0, connecting to a malicious Codespace with gh codespace jupyter can allow command execution because the command opens a JupyterLab URL supplied by a process inside the Codespace without validating that it is a loopbac...

CVE-2026-59831 GitHub CLI `gh codespace jupyter` could allow remote code execution when connecting to a malicious Codespace

GitHub CLI gh is GitHub’s official command line tool. From 2.10.0 through 2.95.0, connecting to a malicious Codespace with gh codespace jupyter can allow command execution because the command opens a JupyterLab URL supplied by a process inside the Codespace without validating that it is a loopbac...