Uncontrolled Recursion in nest - CVE-2026-40879
Published: April 14, 2026
Vulnerability identifier: #VU125898
CSH Severity: Medium
CVSS v4 BT: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2026-40879
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled recursion in JsonSocket handleData() in the TCP transport when processing many small valid JSON messages in a single TCP frame. A remote attacker can send many small valid JSON messages in one TCP frame to cause a denial of service.
A payload of approximately 47 KB can trigger a RangeError because the call stack overflows before maxBufferSize is reached.
Affected software
nest
How to mitigate CVE-2026-40879
Install security update from vendor's website.
nest - update to 11.1.19