{"id":"CVE-2019-11921","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-11921","generatedAt":"2026-10-29T00:07:54.687Z","title":"An out of bounds write is possible via a specially crafted packet in certain configurations of Proxygen due to improper handling of Base64 when parsing malformed binary content in Structured HTTP Headers.","description":"An out of bounds write is possible via a specially crafted packet in certain configurations of Proxygen due to improper handling of Base64 when parsing malformed binary content in Structured HTTP Headers. This issue affects versions of proxygen prior to v2019.07.22.00.","published":"2019-07-25T21:15:12.000Z","lastModified":"2026-06-17T02:13:50.000Z","status":"Modified","sourceIdentifier":"cve-assign@fb.com","cvss":{"version":"3.0","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-787"],"affected":["facebook/proxygen"],"epss":{"score":0.02077,"percentile":0.81381,"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 (2.08%). 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/proxygen/commit/2f07985bef9fbae124cc63e5c0272e32da4fdaec","tags":["Patch","Third Party Advisory"],"source":"cve-assign@fb.com"},{"url":"https://www.facebook.com/security/advisories/cve-2019-11921","tags":["Third Party Advisory"],"source":"cve-assign@fb.com"},{"url":"https://github.com/facebook/proxygen/commit/2f07985bef9fbae124cc63e5c0272e32da4fdaec","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.facebook.com/security/advisories/cve-2019-11921","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-11921","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."}