Answer in brief
CVE-2026-123866 records a High severity (CVSS 7.5) vulnerability in Node.js is vulnerable to HTTP/2 response memory disclosure via a use-after-free during stream teardown. The current sources do not mark it as known exploited. The current feed maps nodejs/node (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps nodejs/node (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| nodejs/nodegeneric | >=0.0.0 <22.23.5 || >=23.0.0 <24.22.3 || >=25.0.0 <26.13.1 | 22.23.5, 24.22.3, 26.13.1 |
Published upstream
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 11, 2026
A use-after-free in Node.js HTTP/2 stream teardown can leak response memory, including the contents of other connections' response buffers, to a peer. When a stream is torn down while a write is still backpressured, for example by a peer RST_STREAM or by the server's own per-stream timeout destroying the stream, the stream's response buffer is freed but a reference to it is still used, so freed or unrelated heap memory is written to the socket instead of the intended response. On Node.js 26.x and 24.x the teardown can be driven purely by a remote peer once the window-size change from 26.9.0 and 24.22.0 is present, and on all supported lines the same defect is reachable through an application-initiated teardown such as a per-stream idle timeout. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Quoted source text, attributed separately from HOL analysis.