{"id":"CVE-2021-42697","details":"Akka HTTP 10.1.x before 10.1.15 and 10.2.x before 10.2.7 can encounter stack exhaustion while parsing HTTP headers, which allows a remote attacker to conduct a Denial of Service attack by sending a User-Agent header with deeply nested comments.","aliases":["GHSA-3hw2-h67c-wq66"],"modified":"2026-07-09T06:34:59.669080Z","published":"2021-11-02T22:15:08.957Z","references":[{"type":"ADVISORY","url":"https://akka.io/blog/"},{"type":"ADVISORY","url":"https://akka.io/blog/news/2021/11/02/akka-http-10.2.7-released"},{"type":"ADVISORY","url":"https://akka.io/blog/news/2021/11/22/akka-http-10.1.15-released"},{"type":"ADVISORY","url":"https://doc.akka.io/docs/akka-http/current/security/2021-CVE-2021-42697-stack-overflow-parsing-user-agent.html"},{"type":"EVIDENCE","url":"http://packetstormsecurity.com/files/167018/Akka-HTTP-10.1.14-Denial-Of-Service.html"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/akka/akka-http","events":[{"introduced":"3bd4b8a9566a8de9ecd730b50552b580ba3fe4c2"},{"fixed":"5243345ff8eeb2ad7663bbb2a1d6e217a725afda"},{"introduced":"80ebb83d75f1c6c45ded2901efbe97dd43c2051d"},{"fixed":"df3dbfbb8344844fdf4f9a2b3d8aebe3793bfc56"}],"database_specific":{"cpe":"cpe:2.3:a:akka:http_server:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"10.1.0"},{"fixed":"10.1.15"},{"introduced":"10.2.0"},{"fixed":"10.2.7"}],"source":"CPE_RANGE"}}],"versions":["v10.2.6","v10.2.5","v10.2.5-M2","v10.2.5-M1","v10.1.14","v10.2.4","v10.2.3","v10.2.2","v10.1.13","v10.2.1","v10.2.0","v10.1.12","v10.1.11","v10.1.10","v10.1.9","v10.1.8","v10.1.7","v10.1.6","v10.1.5","v10.1.4","v10.1.3","v10.1.2","v10.1.1","v10.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-42697.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}