CVE-2026-33979

HIGH SEVERITY

CVSS Score & Metrics

Base Score

8.2 / 10

Vector String

                                        CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N                                    

Vulnerability Description

Express XSS Sanitizer is Express 4.x and 5.x middleware which sanitizes user input data (in req.body, req.query, req.headers and req.params) to prevent Cross Site Scripting (XSS) attack. A vulnerability has been identified in versions prior to 2.0.2 where restrictive sanitization configurations are silently ignored. In version 2.0.2, the validation logic has been updated to respect explicitly provided empty configurations. Now, if allowedTags or allowedAttributes are provided (even if empty), they are passed directly to sanitize-html without being overridden.

Vulnerability Details

Published Date

March 27, 2026

Last Modified

March 31, 2026

CWE ID

CWE-79

Source

GitHub

Vendor

npm

Product

express-xss-sanitizer

External References

https://github.com/AhmedAdelFahim/express-xss-sanitizer/security/advisories/GHSA-3843-rr4g-m8jq
https://github.com/AhmedAdelFahim/express-xss-sanitizer/commit/5623009ef11dcf095c163a38dea07b9cc22ad19f
https://github.com/AhmedAdelFahim/express-xss-sanitizer/releases/tag/v2.0.2
https://github.com/advisories/GHSA-3843-rr4g-m8jq

CVE-2026-33979

CVSS Score & Metrics

Vulnerability Description

Vulnerability Details

External References

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