{"id":"CVE-2026-44214","aliases":["GHSA-m9g3-3g99-mhpx"],"url":"https://o3.security/vulnerability/CVE-2026-44214","summary":"eventsource-encoder: SSE event injection via unsanitized event and id fields","details":"eventsource-encoder encodes events as well-formed EventSource/Server Sent Event (SSE) messages. Prior to 1.0.2, eventsource-encoder does not sanitize the event or id fields of an EventSourceMessage before serializing them. An attacker who controls either field can inject arbitrary Server-Sent Events line terminators (\\n, \\r, or \\r\\n) and thereby forge additional SSE fields or entire messages on the stream. This vulnerability is fixed in 1.0.2.","published":"2026-05-26T19:34:32.273Z","modified":"2026-08-07T11:50:47.471257364Z","cvss":{"score":5.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"eventsource-encoder","fixedVersion":"1.0.2"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44214.json"},{"type":"ADVISORY","url":"https://github.com/rexxars/eventsource-encoder/security/advisories/GHSA-m9g3-3g99-mhpx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44214"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:50:47.471257364Z"}}