Inclusion of Sensitive Information in Log Files in Jupyter Server - #VU146867
Published: September 3, 2026
Vulnerability identifier: #VU146867
CSH Severity: Low
CVSS v4: 7.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-532
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to insertion of sensitive information into log files in jupyter_server/log.py when logging request headers for requests that return a 500 error. A remote user can send a malformed request with a token-bearing Referer header to disclose sensitive information.
User interaction is required during normal token-based login and launch flows that place the token in the Referer URL.
Affected software
Jupyter Server
Remediation
Install security update from vendor's website.
Jupyter Server - update to 2.21.0