CVE-2026-33691
The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web application firewalls.
Published Apr 2, 2026 · updated Jul 24, 2026 · owasp owasp modsecurity core rule set
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.
Code
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Timeline
Detection, updates, and resolution for this record.
Apr 2, 2026 · NIST NVD
Detected
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 white
Jul 24, 2026 · NIST NVD
Updated
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 white
Affected
- cpe owasp/owasp modsecurity core rule setversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-33691
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-33691
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
nvd.nist.gov