CVE Catalog

CVE-2026-44214

MediumCVSS 5.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.28%

20th percentile - higher than 20% of all known CVEs

Summary

In eventsource-encoder prior to 1.0.2, the event and id fields of an EventSourceMessage are not sanitized before serialization. An attacker controlling either field can inject arbitrary Server-Sent Events line terminators and forge additional SSE fields or entire messages.

Risk Assessment

An attacker can manipulate the SSE stream, potentially leading to event forgery or information disclosure in applications using this format.

Recommendation

Update the eventsource-encoder library to version 1.0.2 or later.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS