{"id":"CVE-2019-16770","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-16770","generatedAt":"2026-10-27T23:27:44.130Z","title":"In Puma before versions 3.12.2 and 4.3.1, a poorly-behaved client could use keepalive requests to monopolize Puma's reactor and create a denial of service attack.","description":"In Puma before versions 3.12.2 and 4.3.1, a poorly-behaved client could use keepalive requests to monopolize Puma's reactor and create a denial of service attack. If more keepalive connections to Puma are opened than there are threads available, additional connections will wait permanently if the attacker sends requests frequently enough. This vulnerability is patched in Puma 4.3.1 and 3.12.2.","published":"2019-12-05T20:15:10.000Z","lastModified":"2026-06-17T02:22:46.000Z","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:N/A:H"},"cwe":["CWE-770"],"affected":["puma/puma","debian/debian linux"],"epss":{"score":0.02014,"percentile":0.80759,"date":"2026-10-26","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 (2.01%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/puma/puma/security/advisories/GHSA-7xx3-m584-x994","tags":["Mitigation","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://lists.debian.org/debian-lts-announce/2022/05/msg00034.html","tags":["Mailing List","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/puma/puma/security/advisories/GHSA-7xx3-m584-x994","tags":["Mitigation","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2022/05/msg00034.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-16770","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."}