CVE-2026-40879
Nest Affected by DoS via Recursive handleData in JsonSocket (TCP Transport)
7.5
HIGH
CVSS 3.1
EPSS 0.06%
Description
### Impact Attacker sends many small, valid JSON messages in one TCP frame → handleData() recurses once per message; buffer shrinks each call → maxBufferSize is never reached; call stack overflows instead → A ~47 KB payload is sufficient to trigger RangeError ### Patches Fixed in `@nestjs/[email protected]` ### References Discovered by https://github.com/hwpark6804-gif
How to fix CVE-2026-40879
To remediate CVE-2026-40879, upgrade the affected package to a fixed version below.
- —upgrade to 11.1.19 or later
Is CVE-2026-40879 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 11.1.19
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |