{"id":"CVE-2018-6335","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-6335","generatedAt":"2026-10-28T20:26:16.401Z","title":"This behavior can lead to denial-of-service.","description":"A Malformed h2 frame can cause 'std::out_of_range' exception when parsing priority meta data. This behavior can lead to denial-of-service. This affects all supported versions of HHVM (3.25.2, 3.24.6, and 3.21.10 and below) when using the proxygen server to handle HTTP2 requests.","published":"2018-12-31T19:29:00.000Z","lastModified":"2026-06-17T02:01:41.000Z","status":"Modified","sourceIdentifier":"cve-assign@fb.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:N/A:H"},"cwe":["CWE-400","CWE-20"],"affected":["facebook/hhvm"],"epss":{"score":0.01469,"percentile":0.73591,"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":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/facebook/hhvm/commit/4cb57dd753a339654ca464c139db9871fe961d56","tags":["Patch","Third Party Advisory"],"source":"cve-assign@fb.com"},{"url":"https://hhvm.com/blog/2018/05/04/hhvm-3.25.3.html","tags":["Vendor Advisory"],"source":"cve-assign@fb.com"},{"url":"https://github.com/facebook/hhvm/commit/4cb57dd753a339654ca464c139db9871fe961d56","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hhvm.com/blog/2018/05/04/hhvm-3.25.3.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-6335","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."}