CVE-2026-44214
eventsource-encoder: SSE event injection via unsanitized event and id fields
MEDIUM 5.3EPSS 0.3%
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.
- Affected
- rexxars · eventsource-encoder
- CVSS v3.1 NVD
- 5.3 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - CVSS v3.1 GITHUB
- 5.8 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - EPSS
- 0.32% chance of exploitation in the next 30 days, 24th percentile
- Published
- 2026-05-26
- Updated
- 2026-05-27