CVE-2026-44214
eventsource-encoder: SSE event injection via unsanitized event and id fields
CVSS Score
5.8
EPSS Score
0.0%
EPSS Percentile
1th
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.
| CWE | CWE-93 CWE-113 |
| Vendor | rexxars |
| Product | eventsource-encoder |
| Published | May 26, 2026 |
| Last Updated | May 27, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
rexxars / eventsource-encoder
< 1.0.2