CVE-2026-90561: strapi strapi

Strapi 4.x through 4.26.2 and 5.x before 5.48.1 Stored XSS via WYSIWYG

CVSS 9.3 CriticalCriticalEPSS 0.0043 · 37th percentile

Critical, because:

CVSS score 9.3: 9.0 or more.

Published by the CVE Program (CNA: VulnCheck) at 13 Sept 2026, 10:45 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
strapi	strapi pkg:npm/%40strapi/strapi	affected 4.0.0 to 4.26.2, inclusive semver affected 5.0.0 to before 5.48.1 semver Other versions: unaffected

Identifiers

CVE-2026-90561

CNA

VulnCheck

Weakness (CWE)

CWE-79

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.3	Critical	4.0	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	CNA (VulnCheck)Used for this record
8.7	High	3.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0043, the 37th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 13 Sept 2026. New records show when each source confirmed them.

Sources

References from the CNA

github.com/strapi/strapi/issues/26857 issue-tracking
github.com/strapi/strapi product
github.com/strapi/strapi/blob/v5.46.0/packages/core/content-manager/admin/src/pages/EditView/components/FormInputs/Wysiwyg/PreviewWysiwyg.tsx technical-description
github.com/strapi/strapi/commit/875752612c30f951546904a29469e51e17e0ac37 patch
www.vulncheck.com/advisories/strapi-4-x-through-4.26.2-and-5-x-before-5.48.1-stored-xss-via-wysiwyg third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.