What’s Vulnerable › Vulnerabilities
CVE-2026-40879: Nest: DoS via Recursive handleData in JsonSocket (TCP Transport)
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-21 · updated 2026-10-26
- Weakness: CWE-674
Description
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.
Affected products
- nestjs nest: before 11.1.19 — fixed in 11.1.19
How to fix
Upgrade to a fixed version: nestjs nest 11.1.19. Check the vendor advisory for mitigations.
References
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