The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass to sequentially exfiltrate small and undetectable sections of data by repeatedly submitting an HTTP Range header field with a small byte range. A restricted resource, access to which would ordinarily be detected, may be exfiltrated from the backend, despite being protected by a web application firewall that uses CRS. Short subsections of a restricted resource may bypass pattern matching techniques and allow undetected access. The legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively and to configure a CRS paranoia level of 3 or higher.
Conclusion & alert: CVE-2022-39958 is rated Moderate Risk (54.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.57%). 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 | 2026-05-24 | 0.46% | 0.57% | +0.11% |
| 2 | 2026-05-23 | 0.16% | 0.46% | +0.30% |
| 3 | 2026-01-05 | — | 0.16% | — |
Full EPSS history (19 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2022-39958 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-2022-39958 |
gentoo
|
low | CVE-2022-39958: 1 GLSA(s) (202305-25), 1 atom(s) (www-apache/modsecurity-crs); latest impact low. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-39958 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2022-39958 |
suse
|
high | — | https://www.suse.com/security/cve/CVE-2022-39958/ |
ubuntu
|
low | CVE-2022-39958 low 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-2022-39958 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| owasp | owasp_modsecurity_core_rule_set | >= 3.0.0, < 3.2.2 | cpe:2.3:a:owasp:owasp_modsecurity_core_rule_set:*:*:*:*:*:*:*:* |
| owasp | owasp_modsecurity_core_rule_set | >= 3.3.0, < 3.3.3 | cpe:2.3:a:owasp:owasp_modsecurity_core_rule_set:*:*:*:*:*:*:*:* |
| fedoraproject | fedora | 35 | cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* |
| fedoraproject | fedora | 36 | cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* |
| fedoraproject | fedora | 37 | cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:* |
| debian | debian_linux | 10.0 | cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* |