{"id":"CVE-2026-33691","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-33691","generatedAt":"2026-10-28T04:46:09.532Z","title":"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 ).","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.","published":"2026-04-02T16:16:23.000Z","lastModified":"2026-07-24T21:10:00.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-178"],"affected":["owasp/owasp modsecurity core rule set"],"epss":{"score":0.03845,"percentile":0.90073,"date":"2026-10-27","history":[{"date":"2026-09-24","score":0.01578,"percentile":0.7441},{"date":"2026-10-25","score":0.03845,"percentile":0.90053}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (3.84%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/coreruleset/coreruleset/commit/2a8c63512811c5dd74472becebb79a783e68ff02","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/coreruleset/coreruleset/pull/4546","tags":["Issue Tracking","Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/coreruleset/coreruleset/pull/4547","tags":["Issue Tracking","Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/coreruleset/coreruleset/pull/4548","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/coreruleset/coreruleset/releases/tag/v3.3.9","tags":["Product","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/coreruleset/coreruleset/releases/tag/v4.25.0","tags":["Product","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/coreruleset/coreruleset/security/advisories/GHSA-rw5f-9w43-gv2w","tags":["Mitigation","Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"http://seclists.org/fulldisclosure/2026/Apr/0","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2026/03/29/2","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2026/04/18/4","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-33691","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}