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Fencer Intel
medium 6.4

CVE-2026-124491 json

SunEditor before 3.4.0 Stored XSS via FileUpload Plugin Filename

published 19d ago modified 2d ago also EUVD-2026-119546 , GHSA-2w4v-r3v4-f5h4

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository JiHong88/suneditor. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
6.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in the FileUpload plugin create() method that assigns server-returned file names to innerHTML without escaping. Attackers can upload files with HTML-laden names that bypass html.clean() and execute JavaScript in victims' browsers when content or gallery items load, enabling session theft.

Patch / fix

  • JiHong88 suneditor 3.4.0

Is CVE-2026-124491 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2d ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/JiHong88/suneditor/security/advisories/GHSA-2w4v-r3v4-f5h4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA 3.1 6.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Inferred packages

No advisory lists a package for this vulnerability yet. The CVE names these as products and links their GitHub repository, and the package registry names the same repository, so they are probably the affected packages. Low confidence: the versions are the CVE’s own for the product, and a stack check reports the package as unchecked when there are none.

ecosystem package repository affected
npm suneditor jihong88/suneditor
< 3.4.0

Affected products

  • JiHong88 suneditor

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of JiHong88/suneditor published their own advisory on GitHub. Reviewed sources take precedence over it.