CVE-2026-35515

Nest is a framework for building scalable Node.js server-side applications. Prior to 11.1.18, SseStream._transform() interpolates message.type and message.id directly into Server-Sent Events text protocol output without sanitizing newline characters (\r, \n). Since the SSE protocol treats both \r and \n as field delimiters and \n\n as event boundaries, an attacker who can influence these fields through upstream data sources can inject arbitrary SSE events, spoof event types, and corrupt reconnection state. This vulnerability is fixed in 11.1.18.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact LOW

Scope CHANGED

References

Link	Resource
https://github.com/nestjs/nest/security/advisories/GHSA-36xv-jgw5-4q75	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:nestjs:nest:*:*:*:*:*:node.js:*:*

History

26 Oct 2026, 21:10

Type	Values Removed	Values Added
Summary		(es) Nest es un framework para construir aplicaciones escalables de Node.js del lado del servidor. Antes de la versión 11.1.18, SseStream._transform() interpola message.type y message.id directamente en la salida del protocolo de texto de Server-Sent Events sin sanear los caracteres de nueva línea (\r, \n). Dado que el protocolo SSE trata tanto \r como \n como delimitadores de campo y \n\n como límites de evento, un atacante que pueda influir en estos campos a través de fuentes de datos ascendentes puede inyectar eventos SSE arbitrarios, suplantar tipos de eventos y corromper el estado de reconexión. Esta vulnerabilidad se corrige en la versión 11.1.18.

Information

Published : 2026-04-07 16:16

Updated : 2026-10-26 21:10

NVD link : CVE-2026-35515

Mitre link : CVE-2026-35515

CVE.ORG link : CVE-2026-35515

JSON object : View

Products Affected

nestjs

nest

CWE

CWE-74

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

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