CVE-2026-123863NVD
Vulnerability Summary
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.
Affected & Patched Versions
- This vulnerability affects all users in active release lines: 24.x, 26.x
- Node.js v24.22.3
- Node.js v26.13.1