CVSS 3.0
7.5 highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NCVE-2026-123866 Node.js is vulnerable to HTTP/2 response memory disclosure via a use-after-free during stream teardown
High (7.5) in nodejs node. EPSS 0.5% estimated probability of exploitation activity in the next 30 days.
On this page
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.
Severity
- EPSS
- 0.5% estimated probability of exploitation activity in the next 30 days; 42nd percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CWE
- CWE-416 Use After Free
- Published
- Modified
- Assigned by
- openjs (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| nodejs node | from 0.0.0 before 22.23.5 |
| nodejs node | from 23.0.0 before 24.22.3 |
| nodejs node | from 25.0.0 before 26.13.1 |
Fix and patched versions
- Red Hat, Alpine, Alpaquita, BellSoft Hardened Containers: fixed package versions per release
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13, 14 | nodejs | no fix listed | DEBIAN-CVE-2026-123866 |
| Ubuntu | 24.04:LTS, 26.04:LTS, 26.10 and 5 more | nodejs | no fix listed | UBUNTU-CVE-2026-123866 |
| Red Hat | hummingbird:1 | nodejs22, nodejs22-bin, nodejs22-docs and 4 more | 1:22.23.5-2.3.2.3.1.hum1 | RHSA-2026:99433 |
| Red Hat | hummingbird:1 | nodejs22-npm | 1:10.9.9-1.22.23.5.2.3.2.3.1.hum1 | RHSA-2026:99433 |
| Red Hat | hummingbird:1 | nodejs24, nodejs24-bin, nodejs24-docs and 3 more | 1:24.22.3-0.1.hum1 | RHSA-2026:99435 |
| Red Hat | hummingbird:1 | nodejs24-npm | 2:11.19.1-1.24.22.3.0.1.hum1 | RHSA-2026:99435 |
| Red Hat | hummingbird:1 | nodejs24-npm-bin | 2:24.22.3-0.1.hum1 | RHSA-2026:99435 |
| Red Hat | hummingbird:1 | nodejs26, nodejs26-bin, nodejs26-docs and 4 more | 1:26.13.1-0.1.hum1 | RHSA-2026:99436 |
| Red Hat | hummingbird:1 | nodejs26-npm | 1:11.20.0-1.26.13.1.0.1.hum1 | RHSA-2026:99436 |
| Alpine | v3.21, v3.22 | nodejs | 22.23.5-r0 | ALPINE-CVE-2026-123866 |
| Alpine | v3.23, v3.24 | nodejs | 24.22.3-r0 | ALPINE-CVE-2026-123866 |
| Alpine | v3.24 | nodejs-current | 26.13.1-r0 | ALPINE-CVE-2026-123866 |
| Alpaquita | stream | nodejs22 | 22.23.5-r0 | BELL-CVE-2026-123866 |
| Alpaquita | stream | nodejs24 | 24.22.3-r0 | BELL-CVE-2026-123866 |
| Alpaquita | stream | nodejs26 | 26.13.1-r0 | BELL-CVE-2026-123866 |
| BellSoft Hardened Containers | stream | nodejs22 | 22.23.5-r0 | BELL-CVE-2026-123866 |
| BellSoft Hardened Containers | stream | nodejs24 | 24.22.3-r0 | BELL-CVE-2026-123866 |
| BellSoft Hardened Containers | stream | nodejs26 | 26.13.1-r0 | BELL-CVE-2026-123866 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Red Hat Security Data © Red Hat, Inc., CC BY 4.0; the Alpine secdb, CC BY-SA 4.0; BellSoft's OSV database, MIT. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu · Red Hat · Alpine · Alpaquita · BellSoft Hardened Containers.
Red Hat
Red Hat rates this Important.
This vulnerability is classified as an Important severity flaw because an unauthenticated remote attacker can trigger memory disclosure across active connections, potentially exposing confidential data from other users' sessions. In Red Hat environments, impact is limited to applications that explicitly enable and expose HTTP/2 services, whereas deployments using standard HTTP/1.1 interfaces are unaffected. Under vulnerable configurations, abrupt stream terminations during pending writes allow freed memory segments to be returned over the network socket.
Terminate HTTP/2 at a reverse proxy and avoid exposing Node.js HTTP/2 directly to untrusted peers. Restrict HTTP/2 endpoints to trusted networks (see CME-202).
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | nodejs22 | Affected | |
| Red Hat Enterprise Linux 10 | nodejs24 | Affected | |
| Red Hat Enterprise Linux 10 | nodejs26 | Affected | |
| Red Hat Enterprise Linux 8 | nodejs:22/nodejs | Affected | |
| Red Hat Enterprise Linux 8 | nodejs:24/nodejs | Affected | |
| Red Hat Enterprise Linux 9 | nodejs:22/nodejs | Affected | |
| Red Hat Enterprise Linux 9 | nodejs:24/nodejs | Affected | |
| Red Hat Enterprise Linux 9 | nodejs:26/nodejs | Affected | |
| Red Hat Hardened Images | hi/nodejs | Under investigation | |
| Red Hat Hardened Images | nodejs20 | Will not fix | |
| Red Hat Hardened Images | nodejs22 | Affected | |
| Red Hat Hardened Images | nodejs24 | Affected | |
| Red Hat Hardened Images | nodejs25 | Will not fix | |
| Red Hat Hardened Images | nodejs26 | Affected | |
| Red Hat Hardened Images | npm12 | Under investigation |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-123866.