CVE-2026-33979: Express XSS Sanitizer: allowedTags/allowedAttributes bypass leads to permissive sanitization (XSS risk)
AhmedAdelFahim · express-xss-sanitizer
Affected: AhmedAdelFahim express-xss-sanitizer · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 34% of scored CVEs
DescriptionCVE.org
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 products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- AhmedAdelFahim · express-xss-sanitizer< 2.0.2
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Published
- March 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-33979 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.