CVE-2026-33691

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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."}, {"lang": "es", "value": "El conjunto de reglas base de OWASP (CRS) es un conjunto de reglas gen\u00e9ricas de detecci\u00f3n de ataques para usar con firewalls de aplicaciones web compatibles. Antes de las versiones 3.3.9 y 4.25.0, se identific\u00f3 un bypass en OWASP CRS que permite la carga de archivos con extensiones peligrosas (.PHP, .phar, .jsp, .jspx) insertando relleno de espacios en blanco en el nombre del archivo (por ejemplo, photo. PHP o shell.jsp ). Las reglas afectadas no normalizan los espacios en blanco antes de evaluar la expresi\u00f3n regular de la extensi\u00f3n de archivo, por lo que la comprobaci\u00f3n de extensi\u00f3n de punto falla al coincidir. Este problema ha sido parcheado en las versiones 3.3.9 y 4.25.0."}], "id": "CVE-2026-33691", "lastModified": "2026-07-24T21:10:00.143", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 4.0, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-33691", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-02T17:38:01.007742Z", "version": "2.0.3"}}]}, "published": "2026-04-02T16:16:22.593", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/coreruleset/coreruleset/commit/2a8c63512811c5dd74472becebb79a783e68ff02"}, {"source": "security-advisories@github.com", "tags": ["Issue Tracking", "Patch"], "url": "https://github.com/coreruleset/coreruleset/pull/4546"}, {"source": "security-advisories@github.com", "tags": ["Issue Tracking", "Patch"], "url": "https://github.com/coreruleset/coreruleset/pull/4547"}, {"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/coreruleset/coreruleset/pull/4548"}, {"source": "security-advisories@github.com", "tags": ["Product", "Release Notes"], "url": "https://github.com/coreruleset/coreruleset/releases/tag/v3.3.9"}, {"source": "security-advisories@github.com", "tags": ["Product", "Release Notes"], "url": "https://github.com/coreruleset/coreruleset/releases/tag/v4.25.0"}, {"source": "security-advisories@github.com", "tags": ["Mitigation", "Patch", "Vendor Advisory"], "url": "https://github.com/coreruleset/coreruleset/security/advisories/GHSA-rw5f-9w43-gv2w"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "http://seclists.org/fulldisclosure/2026/Apr/0"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "http://www.openwall.com/lists/oss-security/2026/03/29/2"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "http://www.openwall.com/lists/oss-security/2026/04/18/4"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-178"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

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