XSS in Anaconda Dask
CVE-2026-23528
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.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (10.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Anaconda Dask
- Dask Distributed — versions < 2026.1.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-23528?
- CVE-2026-23528 is a medium-severity vulnerability in Anaconda Dask, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-01-16.
- How severe is CVE-2026-23528?
- Medium severity. CVSS v3 base score is 6.1 out of 10.