high8.2
CVE-2026-33979
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 S…
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | express-xss-sanitizer | < 2.0.2 | 2.0.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Express Xss Sanitizer Project | Express Xss Sanitizer | before 2.0.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-3843-rr4g-m8jq
- 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://nvd.nist.gov/vuln/detail/CVE-2026-33979