Possible pod name collisions in jupyterhub-kubespawner

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

7.6 · CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2020-15110: 1.11% estimated exploitation activity in the next 30 days; percentile 66.06 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact What kind of vulnerability is it? Who is impacted? JupyterHub deployments using: - KubeSpawner <= 0.11.1 (e.g. zero-to-jupyterhub 0.9.0) and - enabled namedservers (not default), and - an Authenticator that allows: - usernames with hyphens or other characters that require escape (e.g. user-hyphen or user@email), and - usernames which may match other usernames up to but not including the escaped character (e.g. user in the above cases) In this circumstance, certain usernames will be able to craft particular server names which will grant them access to the default server of other users who have matching usernames. Patches Has the problem been patched? What versions should users upgrade to? Patch will be released in kubespawner 0.12 and zero-to-jupyterhub 0.9.1 Workarounds Is there a way for users to fix or remediate the vulnerability without upgrading? KubeSpawner Specify configuration: for KubeSpawner Note for KubeSpawner: this configuration will behave differently before and…

Published by the source

22 Jul 2020, 23:07 UTC

Last modified by the source

8 Jul 2026, 06:28 UTC

Source last checked

26 Oct 2026, 13:17 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-v7m9-9497-p9gr

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-v7m9-9497-p9gr

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# Patch Next advisory brief: CVE-2020-15110

Advisory: Possible pod name collisions in jupyterhub-kubespawner
IDs: CVE-2020-15110, GHSA-v7m9-9497-p9gr
Record: https://patchnext.com/advisories/cve-2020-15110 (revision 3, source checked 26 Oct 2026, 13:17 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: jupyterhub-kubespawner 0.12.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI jupyterhub-kubespawner: affected <= 0.11.1; fixed in 0.12.0

## Suggested inspection (read-only)
- `python -m pip show jupyterhub-kubespawner`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on jupyterhub-kubespawner.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-v7m9-9497-p9gr (OSV record GHSA-v7m9-9497-p9gr lists affected ranges: PyPI jupyterhub-kubespawner >=0 <0.12.0 (fixed))
- Verified: https://github.com/advisories/GHSA-v7m9-9497-p9gr (GitHub-reviewed advisory GHSA-v7m9-9497-p9gr lists affected ranges: PyPI jupyterhub-kubespawner >=0 <=0.11.1)

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