CVE-2026-23528 Dask distributed Vulnerable to Remote Code Execution via Jupyter Proxy and Dashboard
Attackers can execute arbitrary code via XSS in the Dask dashboard when used with Jupyter, requiring user interaction with a malicious link.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-23528?
CVE-2026-23528 is a medium-severity cross-site scripting vulnerability in dask distributed, published on 16 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Dask distributed is a distributed task scheduler for Dask. Prior to 2026.1.0, when Jupyter Lab, jupyter-server-proxy, and Dask distributed are all run together, it is possible to craft a URL which will result in code being executed by Jupyter due to a cross-side-scripting (XSS) bug in the Dask dashboard. It is possible for attackers to craft a phishing URL that assumes Jupyter Lab and Dask may be running on localhost and using default ports. If a user clicks on the malicious link it will open an error page in the Dask Dashboard via the Jupyter Lab proxy which will cause code to be executed by the default Jupyter Python kernel. This vulnerability is fixed in 2026.1.0.
Which versions are affected by CVE-2026-23528?
3 open source packages ship an affected version, including distributed. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
distributed PyPI | All versions | 2026.1.0 |
distributed PyPI | All versions | 2026.1.0 |
distributed PyPI | All versions | 2026.1.0 |
Products include Anaconda Dask.
How do I fix CVE-2026-23528?
Upgrade distributed to 2026.1.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-23528 being exploited?
There is no known exploitation of CVE-2026-23528 in the wild and no public exploit code.
Other vulnerabilities in dask distributed
Sources
Also known as DEBIAN-CVE-2026-23528, GHSA-c336-7962-wfj2, PYSEC-2026-169, UBUNTU-CVE-2026-23528.