VULNERABILITY INTELLIGENCE
CVE-2026-33691
CVSS score6.8 MEDIUM
EPSS probability3.84%
CISA KEVNot currently listed
Published2026-04-02
Last modified2026-07-24
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
Description
The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web application firewalls. Prior to versions 3.3.9 and 4.25.0, a bypass was identified in OWASP CRS that allows uploading files with dangerous extensions (.php, .phar, .jsp, .jspx) by inserting whitespace padding in the filename (e.g. photo. php or shell.jsp ). The affected rules do not normalize whitespace before evaluating the file extension regex, so the dot-extension check fails to match. This issue has been patched in versions 3.3.9 and 4.25.0.
Weakness classification
- security-advisories@github.com: CWE-178
Primary references
- security-advisories@github.com — Patch
- security-advisories@github.com — Issue Tracking, Patch
- security-advisories@github.com — Issue Tracking, Patch
- security-advisories@github.com — Patch
- security-advisories@github.com — Product, Release Notes
- security-advisories@github.com — Product, Release Notes
- security-advisories@github.com — Mitigation, Patch, Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108