PatchTheCVECVE-2026-35397: Jupyter Server is the backend for Jupyter web applications
CVE-2026-35397 is a high-severity flaw (CVSS 8.8) affecting jupyter server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, a path traversal vulnerability in the REST API allows an authenticated user to escape the configured root_dir and access sibling directories whose names begin with the same prefix as the root_dir. For example, with a root_dir named "test", the API permits access to a sibling directory named "testtest" through a crafted request to the /api/contents endpoint
Why this priority
- High severity
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.8 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.6% (top 50%) |
| CISA exploited list | No |
| Weakness | CWE-22 |
| Published | 2026-05-05 |
| Last modified | 2026-08-28 |
Last updated 2026-08-28 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-35397?
jupyter server: upgrade to 2.18.0. Exact commands for each OS are on this page.
Is CVE-2026-35397 being exploited?
CVE-2026-35397 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-35397 affect?
CVE-2026-35397 affects jupyter server. Severity is high (CVSS 8.8). Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, a path traversal vulnerability in the REST API allows an authenticated user to escape the configured root_dir and access sibling directories whose n
How urgent is CVE-2026-35397?
Priority 48/100. High severity; Public exploit reference
Software pages
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