CVE-2026-40879: Nest is a framework for building scalable Node.js server-side applications

Routine

HIGH 7.5REMOTEUPGRADE

CVE-2026-40879 is a high-severity flaw (CVSS 7.5) affecting nest. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-674
Published	2026-04-21
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: nestjs

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-21 20:17 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

nestjs nest UPGRADE

Affected: < 11.1.19

Fixed in: 11.1.19

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls nest

2. UPGRADE to 11.1.19

npm install nest@">=11.1.19"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40879?

nest: upgrade to 11.1.19. Exact commands for each OS are on this page.

Is CVE-2026-40879 being exploited?

CVE-2026-40879 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40879 affect?

CVE-2026-40879 affects nest. Severity is high (CVSS 7.5). 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. max

How urgent is CVE-2026-40879?

Priority 38/100. High severity; Remotely exploitable, no login, no user action

Software pages

Node.js vulnerabilities

Related CVEs

CVE-2026-35515 MEDIUM 6.1 UPGRADE Nest is a framework for building scalable Node.js server-side applications

References

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