CVE-2026-123863
Publication date 12 November 2026
Last updated 13 November 2026
Ubuntu priority
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).
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| nodejs | 26.10 stonking |
Needs evaluation
|
| 26.04 LTS resolute |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
|
| 14.04 LTS trusty |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
8.2 · High
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-123863
- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases#http2-remote-abort-check_eqcurrent_nghttp2_memory_-0-in-http2session-cve-2026-123863---high
- https://cna.openjsf.org/security-advisories.html
- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases