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.
Patched in jupyterhub-systemdspawner v0.15
No workaround other than upgrading systemdspawner to 0.15
If you have any questions or comments about this advisory:
github.com/jupyterhub/systemdspawner/blob/master/CHANGELOG.md#v015
github.com/jupyterhub/systemdspawner/commit/a4d08fd2ade1cfd0ef2c29dc221e649345f23580
github.com/jupyterhub/systemdspawner/security/advisories/GHSA-cg54-gpgr-4rm6
nvd.nist.gov/vuln/detail/CVE-2020-26261
pypi.org/project/jupyterhub-systemdspawner