7.1

CVE-2026-86049

Jupyter Server: 5xx request logging leaks token-bearing Referer header values

Jupyter Server is the backend for Jupyter web applications. Prior to version 2.21.0, the 5xx request logging path in jupyter_server/log.py copies the Referer header into a JSON header block without applying the token scrubbing used for the request URI. A request that returns HTTP 500 while the Referer contains a token-bearing URL can therefore write that token to server logs in plaintext. An attacker who can read those logs can recover the token and use the affected user's Jupyter Server permissions. This issue is fixed in version 2.21.0.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
Herstellerjupyter-server
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Produkt jupyter_server
Version < 2.21.0
Status affected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.24% 0.152
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
security-advisories@github.com 7.1 1.2 5.9
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
CWE-532 Insertion of Sensitive Information into Log File

The product writes sensitive information to a log file.

https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-c3mw-737p-c7g2
https://github.com/jupyter-server/jupyter_server/pull/1681
https://github.com/jupyter-server/jupyter_server/commit/52513529af7096e622c00911b17627b266294717
https://github.com/jupyter-server/jupyter_server/releases/tag/v2.21.0