#VU125025 Injection in nest - CVE-2026-35515
Published: April 7, 2026
Vulnerability identifier: #VU125025
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-35515
CWE-ID: CWE-74
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
nest
nest
Software vendor:
nestjs
nestjs
Description
The vulnerability allows a remote attacker to inject arbitrary SSE events, spoof event types, and corrupt reconnection state.
The vulnerability exists due to improper neutralization of special elements in SseStream._transform() when generating server-sent events output from user-influenced message.type or message.id fields. A remote attacker can supply crafted newline characters in these fields to inject arbitrary SSE events, spoof event types, and corrupt reconnection state.
Exploitation requires developer code that maps user-influenced data into the type or id fields of SSE messages.
Remediation
Install security update from vendor's website.