How severe is CVE-2025-59842?

No CVSS score has been assigned to CVE-2025-59842 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-59842?

CVE-2025-59842 affects the following packages: jupyterlab (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2025-59842?

Update jupyterlab to 4.4.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-59842 is resolved across your whole dependency graph.

How do I detect CVE-2025-59842 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jupyterlab, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-59842 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2025-59842 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-59842 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-59842?

CVE-2025-59842 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 17th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-59842?

CVE-2025-59842 is classified as CWE-1022 (CWE-1022). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-59842 published, and has it been updated?

CVE-2025-59842 was published on September 26, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2025-59842 — jupyterlab

Fix: jupyterlab/jupyterlab@88ef373

CVE-2025-59842 is a CWE-1022 vulnerability in jupyterlab. A fix is available for jupyterlab — see the affected versions and patch details below.

JupyterLab LaTeX typesetter links did not enforce `noopener` attribute

Also known asBIT-jupyterlab-2025-59842GHSA-vvfj-2jqx-52jmPYSEC-2026-1482

Published

Sep 26, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-59842.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk+0.01%

Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐍jupyterlab

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Links generated with LaTeX typesetters in Markdown files and Markdown cells in JupyterLab and Jupyter Notebook did not include the noopener attribute.

This is deemed to have no impact on the default installations. Theoretically users of third-party LaTeX-rendering extensions could find themselves vulnerable to reverse tabnabbing attacks if:

links generated by those extensions included target=_blank (no such extensions are known at time of writing) and
they were to click on a link generated in LaTeX (typically visibly different from other links).

For consistency with handling on other links, new versions of JupyterLab will enforce noopener and target=_blank on all links generated by typesetters. The former will harden the resilience of JupyterLab to extensions with lack of secure defaults in link rendering, and the latter will improve user experience by preventing accidental state loss when clicking on links rendered by LaTeX typesetters.

Impact

Since the official LaTeX typesetter extensions for JupyterLab: jupyterlab-mathjax (default), jupyterlab-mathjax2 and jupyterlab-katex do not include the target=_blank, there is no impact for JupyterLab users.

Patches

JupyterLab 4.4.8

Workarounds

No workarounds are necessary.

References

None

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`jupyterlab`	all versions	4.4.8`pip install --upgrade 'jupyterlab==4.4.8'`

Affected Products

1 product · 1 configurations

Application

jupyterlabjupyter

< 4.4.8

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jupyterlab, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jupyterlab to 4.4.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-59842 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatLow

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: Red Hat security advisory for CVE-2025-59842 (CC BY 4.0)

Frequently Asked Questions

Links generated with LaTeX typesetters in Markdown files and Markdown cells in JupyterLab and Jupyter Notebook did not include the `noopener` attribute. This is deemed to have no impact on the default installations. Theoretically users of third-party LaTeX-rendering extensions could find themselves vulnerable to reverse tabnabbing attacks if: - links generated by those extensions included `target=_blank` (no such extensions are known at time of writing) and - they were to click on a link generated in LaTeX (typically visibly different from other links). For consistency with handling on other

O3 Security · Impact-Aware SCA

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