CVE-2026-40879: high-severity vulnerability in nestjs nest
Nest: DoS via Recursive handleData in JsonSocket (TCP Transport)
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.3%
Nest is a framework for building scalable Node.js server-side applications. Prior to 11.1.19, when an attacker sends many small, valid JSON messages in one TCP frame, handleData() recurses once per message; the buffer shrinks each call. maxBufferSize is never reached; call stack overflows instead. A ~47 KB payload is sufficient to trigger RangeError. This vulnerability is fixed in 11.1.19.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
nestjs · nestRelated CVEs — nestjs nest
In the same product, most dangerous first.
CVE-2025-54782CRITICAL@nestjs/devtools-integration's CSRF to Sandbox Escape Allows for RCE against JS DevelopersEPSS 47.2%CVE-2026-102281HIGHNest: Remote process termination via a deeply nested microservice message patternEPSS 0.6%CVE-2026-54281HIGHNest: Middleware Bypass on Fastify via Trailing SlashEPSS 0.5%CVE-2025-69211MEDIUMNest has a Fastify URL Encoding Middleware Bypass (TOCTOU)EPSS 0.4%CVE-2026-33011HIGHNest Fastify HEAD Request Middleware BypassEPSS 0.4%CVE-2026-35515MEDIUM@nestjs/core Improperly Neutralizes Special Elements in Output Used by a Downstream Component ('Injection')EPSS 0.2%