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GHSA-24qx-w28j-9m6p jupyter-server

Fix: jupyter-server/jupyter_server#603

GHSA-24qx-w28j-9m6p is a CWE-777 vulnerability in jupyter-server. A fix is available for jupyter-server — see the affected versions and patch details below.

Jupyter Server has a CORS Origin Validation Bypass via `re.match()` in `allow_origin_pat`

Also known asCVE-2026-40110PYSEC-2026-2187
Published
May 5, 2026
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 20, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • 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 GHSA-24qx-w28j-9m6p.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs28th percentile — riskier than 28% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected
🐍jupyter-server

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

Jupyter Server uses re.match() to validate the Origin header against the allow_origin_pat configuration.

Since re.match() only anchors at the start of the string, an attacker who controls a domain like http://trusted.example.com.evil.com/ passes validation against a pattern intended to match only trusted.example.com.

Impact

<=2.17.0

Patches

057869a327c46730afede3eab0ca2d2e3e74acea, 49b34392feaa97735b3b777e3baf8f22f2a14ed8

Workarounds

Wrap your allow_origin_pat value with ^ and $

References

https://github.com/jupyter-server/jupyter_server/pull/603 https://docs.python.org/3/library/re.html#re.fullmatch https://docs.python.org/3/library/re.html#re.match

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIjupyter-serverall versions2.18.0pip install --upgrade 'jupyter-server==2.18.0'

Detection & mitigation playbook

Open-source dependency
  1. Detect

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

  2. Fix

    Update jupyter-server to 2.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-24qx-w28j-9m6p is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-24qx-w28j-9m6p can be triaged on real exposure rather than presence alone.

Tailored to GHSA-24qx-w28j-9m6p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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 HatImportant
ProductFixed inAdvisory
Red Hat Migration Toolkit for Applications 8.2mta/mta-solution-server-rhel9:1784109883RHSA-2026:43038

Frequently Asked Questions

Jupyter Server uses `re.match()` to validate the Origin header against the `allow_origin_pat` configuration. Since `re.match()` only anchors at the start of the string, an attacker who controls a domain like `http://trusted.example.com.evil.com/` passes validation against a pattern intended to match only `trusted.example.com`. ### Impact <=2.17.0 ### Patches 057869a327c46730afede3eab0ca2d2e3e74acea, 49b34392feaa97735b3b777e3baf8f22f2a14ed8 ### Workarounds Wrap your `allow_origin_pat` value with `^` and `$` ### References https://github.com/jupyter-server/jupyter_server/pull/603 https
O3 Security · Impact-Aware SCA

Is GHSA-24qx-w28j-9m6p in your dependencies?

O3 Security finds GHSA-24qx-w28j-9m6p across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-24qx-w28j-9m6p: jupyter-server | O3 Security