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CVE-2026-40879

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

Published: Apr 21, 2026Updated: Apr 21, 2026 Sources: CVE List
NVD MITRE
7.5CVSS
HIGH

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.

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High

Weaknesses

CWE-674CWE-674: Uncontrolled Recursion

Affected Products

nest
nestjs

Attack Graph

Products CVE Techniques Tactics

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Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

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

Timeline

Published
Apr 21, 2026
Last Updated
Apr 21, 2026

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