Apache Superset Stored XSS on Dashboard markdown

Exploitation

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

CVSS

5.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2021-27907: 86.39% estimated exploitation activity in the next 30 days; percentile 99.73 (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.

Apache Superset up to and including 0.38.0 allowed the creation of a Markdown component on a Dashboard page for describing chart's related information. Abusing this functionality, a malicious user could inject javascript code executing unwanted action in the context of the user's browser. The javascript code will be automatically executed (Stored XSS) when a legitimate user surfs on the dashboard page. The vulnerability is exploitable creating a “div” section and embedding in it a “svg” element with javascript code.

Published by the source

24 May 2022, 22:29 UTC

Last modified by the source

5 Feb 2025, 09:11 UTC

Source last checked

26 Oct 2026, 13:12 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-w358-rj93-r5qv

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-w358-rj93-r5qv

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# Patch Next advisory brief: CVE-2021-27907

Advisory: Apache Superset Stored XSS on Dashboard markdown
IDs: CVE-2021-27907, GHSA-w358-rj93-r5qv
Record: https://patchnext.com/advisories/cve-2021-27907 (revision 2, source checked 26 Oct 2026, 13:12 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: apache-superset 0.38.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI apache-superset: affected <= 0.38.0; fixed in 0.38.1

## Suggested inspection (read-only)
- `python -m pip show apache-superset`: 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 apache-superset.
- 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-w358-rj93-r5qv (OSV record GHSA-w358-rj93-r5qv lists affected ranges: PyPI apache-superset >=0 <0.38.1 (fixed))
- Verified: https://github.com/advisories/GHSA-w358-rj93-r5qv (GitHub-reviewed advisory GHSA-w358-rj93-r5qv lists affected ranges: PyPI apache-superset >=0 <=0.38.0)

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