CVE-20XX-?
agent?

CVE-2026-86049

7.1 HIGH 0.4% exploit odds Fix listed Disclosure Server

What it is

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.

At a glance

Exploitability
Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering, service disruption.
Exploit odds
0.4% chance of exploitation in the next 30 days (EPSS).
Fix
A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

  1. PublishedDisclosed publicly on CVE.org and NVD
  2. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Exploit probability
0.4% · EPSS, next 30 days
Weakness
CWE-532 · Secrets in logs
Record status
Awaiting Analysis

Attack profile CVSS 3.1 · 7.1

Attack vector
Network
Complexity
High
Privileges needed
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Raw vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-86049.md and follow it. Check whether this project is affected by CVE-2026-86049. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record