CVE-2020-26261

What it is

jupyterhub-systemdspawner enables JupyterHub to spawn single-user notebook servers using systemd. In jupyterhub-systemdspawner before version 0.15 user API tokens issued to single-user servers are specified in the environment of systemd units. These tokens are incorrectly accessible to all users. In particular, the-littlest-jupyterhub is affected, which uses systemdspawner by default. This is patched in jupyterhub-systemdspawner v0.15

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2020-12-09 17:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:07 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 7.9 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2020-12-09 17:15 UTC

Last modified

2026-06-17 03:07 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-668 · Resource exposure

Record status

Modified

Affected

• Jupyterhub Systemdspawner < 0.15

Attack profile CVSS 3.1 · 7.9

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

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-2020-26261.md and follow it. Check whether this project is affected by CVE-2020-26261. 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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