CVE-2026-44214: Rexxars Eventsource-Encoder

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• Rexxars Eventsource-Encoder: before 1.0.2 (fixed in 1.0.2)

Published 2026-05-26. Last modified 2026-07-24.