{"id":"CVE-2025-6442","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-6442","generatedAt":"2026-10-28T10:35:44.654Z","title":"Ruby WEBrick read_header HTTP Request Smuggling Vulnerability.","description":"Ruby WEBrick read_header HTTP Request Smuggling Vulnerability. This vulnerability allows remote attackers to smuggle arbitrary HTTP requests on affected installations of Ruby WEBrick. This issue is exploitable when the product is deployed behind an HTTP proxy that fulfills specific conditions.\n\nThe specific flaw exists within the read_headers method. The issue results from the inconsistent parsing of terminators of HTTP headers. An attacker can leverage this vulnerability to smuggle arbitrary HTTP requests. Was ZDI-CAN-21876.","published":"2025-06-25T17:15:40.000Z","lastModified":"2026-06-17T10:01:54.000Z","status":"Analyzed","sourceIdentifier":"zdi-disclosures@trendmicro.com","cvss":{"version":"3.1","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-444"],"affected":["ruby-lang/webrick"],"epss":{"score":0.00495,"percentile":0.4225,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.50%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864","tags":["Patch"],"source":"zdi-disclosures@trendmicro.com"},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-25-414/","tags":["Third Party Advisory"],"source":"zdi-disclosures@trendmicro.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-6442","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."}