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.
History

Tue, 07 Apr 2026 18:00:00 +0000

Type Values Removed Values Added
Description 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.
Title @nestjs/core Improperly Neutralizes Special Elements in Output Used by a Downstream Component ('Injection')
Weaknesses CWE-74
References
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-07T15:58:37.067Z

Reserved: 2026-04-03T02:15:39.280Z

Link: CVE-2026-35515

cve-icon Vulnrichment

Updated: 2026-04-07T15:49:00.468Z

cve-icon NVD

Status : Received

Published: 2026-04-07T16:16:27.773

Modified: 2026-04-07T16:16:27.773

Link: CVE-2026-35515

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.