What is CVE-2026-40879?

CVE-2026-40879 is a high-severity vulnerability in Nestjs Nest, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2026-04-21.

How severe is CVE-2026-40879?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Nestjs Nest

CVE-2026-40879

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. ma…

EPSS: 0.001 (19.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Nestjs Nest — versions < 11.1.19

Weakness classification (CWE)

CWE-674 — Uncontrolled Recursion

References

https://github.com/nestjs/nest/security/advisories/GHSA-hpwf-8g29-85qm (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-40879?: CVE-2026-40879 is a high-severity vulnerability in Nestjs Nest, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2026-04-21.
How severe is CVE-2026-40879?: High severity. CVSS v3 base score is 7.5 out of 10.