Nest: DoS via Recursive handleData in JsonSocket (TCP Transport)

published 2026-04-14 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-24264 , GHSA-hpwf-8g29-85qm

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits: 0; none known

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.

Patch / fix

fixed in 2

npm @nestjs/microservices 11.1.19
nestjs nest 11.1.19

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-40879 updated 2026-06-28 cvss 7.5

nest: Nest: Denial of Service via recursive JSON message handling

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 6 mo ago (2026-04-21)

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	@nestjs/microservices	<11.1.19	11.1.19

Affected products

nestjs nest

Classification

Weakness

CWE-674 Uncontrolled Recursion
CWE-770 Allocation of Resources Without Limits or Throttling

References

github.com /nestjs/nest/security/advisories/GHSA-hpwf-8g29-85qm
web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2026-40879
advisory
github.com /nestjs/nest
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary