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Fencer Intel
medium 6.4

CVE-2026-4103 json

Cross-Site Scripting via HTML Sanitization in WSO2 Publisher and Developer Portals Allows Malicious Script Execution

published last mo. modified last mo. also EUVD-2026-77586

cvss
6.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

Insufficient HTML sanitization in the Publisher Portal and Developer Portal allows untrusted user input to be rendered without proper encoding or neutralization. This enables the injection and execution of malicious JavaScript when affected API documents are viewed.

Successful exploitation may result in the execution of malicious scripts within the user's browser context when viewing API documentation. Users with permissions to access the API documentation through these portals may be impacted, potentially allowing attackers to perform actions on behalf of the user, depending on their session privileges.

Patch / fix

  • WSO2 WSO2 API Control Plane 4.5.0.55, 4.6.0.19
  • WSO2 WSO2 API Manager 3.2.0.470, 3.2.1.89, 4.1.0.254, 4.2.0.194, 4.3.0.105, 4.4.0.69, 4.5.0.54, 4.6.0.18

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Affected products

  • WSO2 WSO2 API Control Plane
  • WSO2 WSO2 API Manager

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.