SunEditor before 3.4.0 Stored XSS via : Entity Sanitizer Bypass
SunEditor versions before 3.4.0 (npm package suneditor) in the default configuration (strictMode true, all filters enabled) are affected. Fixed in 3.4.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 3.4.0
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. SunEditor versions before 3.4.0 (npm package suneditor) Default configuration (strictMode true, all filters enabled)
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 21/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability because the html.clean() sanitizer's _normalizeURL() function decodes named entities like : to an empty string. Attackers can inject href values such as javascript: that pass the _isSafeURL() check but are decoded by browsers, executing JavaScript when victims click stored links.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.3/10CVSS 9.3
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
What to do
Check whether your setup matches what the bug needs.
SunEditor versions before 3.4.0 (npm package suneditor) Default configuration (strictMode true, all filters enabled)Upgrade to a fixed version: 3.4.0.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- JiHong88 suneditor
fixed in 3.4.0
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-124494
Is CVE-2026-124494 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: cve.now feed data
What does this mean?
A javascript: link injected into stored HTML content gets past SunEditor's sanitizer, so arbitrary JavaScript can run in the browser session of the host application. This can lead to session cookie theft and account takeover.Source: vulncheck.com, github.com
Which versions are affected by CVE-2026-124494?
suneditor: before 3.4.0.Source: cve.now feed data
Am I affected, and how do I check?
The affected range is the suneditor npm package before 3.4.0, in the default configuration with strictMode true and all filters enabled. To check a setup, look at the suneditor version in package.json or the lockfile, and at the strictMode and filter settings in the editor configuration.Source: vulncheck.com, github.com
How do I fix CVE-2026-124494?
Upgrade the suneditor npm package to 3.4.0 or later, which is the fixed version.Source: vulncheck.com, github.com