8.2
HIGH CVSS 3.0
CVE-2026-123863
Node.js is vulnerable to a remote HTTP/2 denial of service via a reachable assertion in Http2Session teardown
Description

A reachable assertion in Node.js HTTP/2 session teardown lets any unauthenticated client abort the server, over both TLS and cleartext. A client can arrange for an Http2Stream that still holds nghttp2-allocated header buffers to outlive its session: the stream is removed from the session's stream set but never detached, so when ~Http2Session() runs the memory accounting is nonzero and the CHECK_EQ(current_nghttp2_memory_, 0) assertion fails, terminating the process. The trigger needs only a default http2 server whose handler responds before the request body has ended, which is typical. It is a variant of CVE-2024-27983 that the earlier fix did not cover, because that fix only detached streams still tracked in the session. This vulnerability affects Node.js 26.x (since 26.9.0) and 24.x (since 24.22.0).

INFO

Published Date :

Nov. 11, 2026, 6:16 p.m.

Last Modified :

Nov. 11, 2026, 6:16 p.m.

Remotely Exploit :

Yes !

Source :

openjs
Affected Products

The following products are affected by CVE-2026-123863 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Nodejs node.js
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.0 HIGH ce714d77-add3-4f53-aff5-83d477b104bb
CVSS 3.0 HIGH MITRE-CVE
Solution
Update Node.js to a patched version to prevent denial-of-service via assertion failure.
  • Update Node.js to version 26.9.0 or later.
  • Update Node.js to version 24.22.0 or later.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-123863 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.