coreruleset (aka OWASP ModSecurity Core Rule Set) through 3.3.4 does not detect multiple Content-Type request headers on some platforms. This might allow attackers to bypass a WAF with a crafted payload, aka "Content-Type confusion" between the WAF and the backend application. This occurs when the web application relies on only the last Content-Type header. Other platforms may reject the additional Content-Type header or merge conflicting headers, leading to detection as a malformed header.
Conclusion & alert: CVE-2023-38199 is rated Moderate Risk (55.6/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.63%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.04% | 0.63% | +0.59% |
| 2 | 2025-11-21 | 0.32% | 0.04% | -0.28% |
| 3 | 2025-11-18 | — | 0.32% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2023-38199 not yet assigned priority: Debian including 1 source packages (modsecurity-crs), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2023-38199 |
ubuntu
|
medium | CVE-2023-38199 medium priority: Ubuntu including 1 source packages (modsecurity-crs), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 7, ignored 6. | https://ubuntu.com/security/CVE-2023-38199 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| owasp | coreruleset | <= 3.3.4 | cpe:2.3:a:owasp:coreruleset:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/coreruleset/coreruleset/issues/3191 | Issue Tracking Patch |
| https://github.com/coreruleset/coreruleset/pull/3237 | Issue Tracking |