---
id: CVE-2020-26261
aliases:
  - GHSA-cg54-gpgr-4rm6
  - PYSEC-2020-52
title: user-readable api tokens in systemd units for JupyterHub
summary: user-readable api tokens in systemd units for JupyterHub
severity: high
cvss: 7.9
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N'
vendor: jupyterhub-systemdspawner
product: jupyterhub-systemdspawner
ecosystem: pip
affected:
  - jupyterhub-systemdspawner < 0.15.0
patched:
  - jupyterhub-systemdspawner 0.15.0
published: '2020-12-09'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:49:00.478208411Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-cg54-gpgr-4rm6'
references:
  - url: >-
      https://github.com/jupyterhub/systemdspawner/security/advisories/GHSA-cg54-gpgr-4rm6
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2020-26261'
  - url: >-
      https://github.com/jupyterhub/systemdspawner/commit/a4d08fd2ade1cfd0ef2c29dc221e649345f23580
  - url: 'https://github.com/jupyterhub/systemdspawner'
  - url: 'https://github.com/jupyterhub/systemdspawner/blob/master/CHANGELOG.md#v015'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/jupyterhub-systemdspawner/PYSEC-2020-52.yaml
  - url: 'https://pypi.org/project/jupyterhub-systemdspawner'
tags:
  - osv
  - pip
epss: 0.0048
epssPercentile: 0.38767
ingestedAt: '2026-09-12T03:13:01.687Z'
---

## Overview

### Impact
user API tokens issued to single-user servers are specified in the environment of systemd units, which are accessible to all users.

In particular, the-littlest-jupyterhub is affected, which uses systemdspawner by default.

### Patches
Patched in jupyterhub-systemdspawner v0.15

### Workarounds
No workaround other than upgrading systemdspawner to 0.15

### For more information

If you have any questions or comments about this advisory:
* Open a thread in [the Jupyter forum](https://discourse.jupyter.org)
* Email us at [security@ipython.org](mailto:security@ipython.org)

## Affected packages

- `jupyterhub-systemdspawner < 0.15.0`

## Remediation

Upgrade to a patched release:

- `jupyterhub-systemdspawner 0.15.0`