SB2026040728 - Code injection in nestjs nest

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Main Vulnerability Database SB2026040728

SB2026040728 - Code injection in nestjs nest

Published: April 7, 2026

Security Bulletin ID SB2026040728
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Injection (CVE-ID: CVE-2026-35515)

CWE-ID: CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSSv4: 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


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 update from vendor's website.

References