CVE-2026-44214CWE-113CWE-93
eventsource-encoder: SSE event injection via unsanitized event and id fields
Medium · published May 26, 2026
What it is
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.
The record
Technical detail
- CVSS v3.1
- 5.8 · MEDIUM
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- CVSS v4.0
- Not supplied
- EPSS
- 0.00320 · 23.9th percentile
- Weaknesses
- CWE-113 · Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting'); CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')
- Published
- 2026-05-26T19:34Z
EPSS history
Timeline