# CVE-2026-124422: SunEditor 3.0.0 before 3.4.0 Stored XSS via html.clean() Iframe Placeholder

Status: published. Published: 2026-11-08. Updated: 2026-11-08.

SunEditor from 3.0.0 before 3.4.0 contains a stored cross-site scripting vulnerability in html.clean() that rebuilds iframes from data-se-iframe-holder-attrs JSON without filtering srcdoc or uppercase SRC keys. Attackers can inject crafted HTML through paste, html.set, or html.insert to execute script in the host page origin when victims load or paste the content.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/JiHong88/suneditor/commit/57db24ac218cd10942fed0bb8288e9cb40b334bb

## Affected products and versions

- jihong88 / suneditor (suneditor): ≥ 3.0.0; < 3.4.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 5.3 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.1 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-79

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/JiHong88/suneditor/security/advisories/GHSA-q867-q2hw-f8gp (CNA: VulnCheck; vendor-advisory)

- https://github.com/JiHong88/suneditor/commit/57db24ac218cd10942fed0bb8288e9cb40b334bb (CNA: VulnCheck; patch)

- https://github.com/JiHong88/suneditor/releases/tag/3.4.0 (CNA: VulnCheck; release-notes)

- https://github.com/JiHong88/suneditor/blob/3.3.3/src/core/logic/dom/html.js#L336-L350 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/suneditor-3.0.0-before-3.4.0-stored-xss-via-html-clean-iframe-placeholder (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-124422; retrieved 2026-11-08; source updated 2026-11-08

Revision: 71ac0257e6afdd160b1161f31b34f90460a9a472fe22af372545e36dd13a3c60

Canonical: https://y2.dev/cve/CVE-2026-124422

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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