Prototype pollution in express-xss-sanitizer
Priority HIGH 65CWE-1321Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
The package express-xss-sanitizer before 1.1.3 are vulnerable to Prototype Pollution via the allowedTags attribute, allowing the attacker to bypass xss sanitization.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00954 61st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed express-xss-sanitizer: 1.1.3express-xss-sanitizer (npm): 1.1.3
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | express-xss-sanitizer | before 1.1.3 | 1.1.3 | Patch available | CNA |
| — | express-xss-sanitizer (npm) | before 1.1.3 | 1.1.3 | Patch available | GHSA-grjp-4jmr-mjcw |
- express-xss-sanitizer Vendor— Affected before 1.1.3 Fixed in 1.1.3 Patch available CNA
- express-xss-sanitizer (npm) Vendor— Affected before 1.1.3 Fixed in 1.1.3 Patch available GHSA-grjp-4jmr-mjcw
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:express_xss_sanitizer_project:express_xss_sanitizer:*:*:*:*:*:node.js:*:* | before 1.1.3 | Vulnerable | Express XSS Sanitizer project |
- cpe:2.3:a:express_xss_sanitizer_project:express_xss_sanitizer:*:*:*:*:*:node.js:*:* Versions before 1.1.3 Vulnerable ·Express XSS Sanitizer project
Remediation
- Fix · CNA express-xss-sanitizer Fixed in 1.1.3
- Fix · GHSA-grjp-4jmr-mjcw express-xss-sanitizer (npm) Fixed in 1.1.3 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2022-21169
- 2026-10-03 Alias added: GHSA-grjp-4jmr-mjcw
References
Patch 2
More Express XSS Sanitizer project Express Xss Sanitizer vulnerabilities
- TI-2026-26320 Express XSS Sanitizer: allowedTags/allowedAttributes bypass leads to permissive sanitization (XSS risk) CVSS 3.1HIGH 8.2
Sources
- CVE-2022-21169 · CVE Program
- CVE-2022-21169 · NVD
- FIRST EPSS
- GHSA-grjp-4jmr-mjcw · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences