CVSS 3.0
8.1 highCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:HCVE-2026-123864 Node.js is vulnerable to cross-connection memory disclosure via TLS write re-entrancy in the HTTPS request parser
High (8.1) in nodejs node. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
On this page
A re-entrancy flaw in Node.js HTTPS lets an unauthenticated client read memory belonging to other connections, including TLS private keys and other users' requests. TLSWrap::DoWrite() calls ClearOut() directly when asked to write zero bytes; if that write is issued from JavaScript running inside the HTTP parser's on_body callback, ClearOut() decrypts the next TLS record while the parser is still mid-body, re-entering llhttp_execute() and causing a use-after-free and an out-of-bounds heap read. The server then copies that freed or unrelated heap memory into the response for the request body. Triggering it requires a handler that calls res.flushHeaders() before the request body ends and later calls res.end() with a non-empty chunk, and reading the leaked memory requires any ordinary route that echoes or stores a request body. Cleartext node:http is not affected. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Severity
- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 27th 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-2026-123864 |
| Ubuntu | 24.04:LTS, 26.04:LTS, 26.10 and 5 more | nodejs | no fix listed | UBUNTU-CVE-2026-123864 |
| 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-2026-123864 |
| Alpine | v3.23, v3.24 | nodejs | 24.22.3-r0 | ALPINE-CVE-2026-123864 |
| Alpine | v3.24 | llhttp | 9.4.4-r0 | ALPINE-CVE-2026-123864 |
| Alpine | v3.24 | nodejs-current | 26.13.1-r0 | ALPINE-CVE-2026-123864 |
| Alpaquita | stream | nodejs22 | 22.23.5-r0 | BELL-CVE-2026-123864 |
| Alpaquita | stream | nodejs24 | 24.22.3-r0 | BELL-CVE-2026-123864 |
| Alpaquita | stream | nodejs26 | 26.13.1-r0 | BELL-CVE-2026-123864 |
| BellSoft Hardened Containers | stream | nodejs22 | 22.23.5-r0 | BELL-CVE-2026-123864 |
| BellSoft Hardened Containers | stream | nodejs24 | 24.22.3-r0 | BELL-CVE-2026-123864 |
| BellSoft Hardened Containers | stream | nodejs26 | 26.13.1-r0 | BELL-CVE-2026-123864 |
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 rated as Important rather than Moderate because an unauthenticated remote attacker can trigger heap memory corruption across concurrent sessions, potentially leaking sensitive data such as private cryptographic keys or request payloads belonging to other users. However, successful exploitation requires high attack complexity, as the target application must implement specific streaming and header-flushing behaviors during request body processing. Node.js deployments serving unencrypted HTTP or terminating TLS at an external gateway remain unaffected by this flaw.
Offload TLS termination to a trusted reverse proxy or load balancer and serve cleartext HTTP from Node.js on localhost only. Restrict direct HTTPS exposure to untrusted clients.
| 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 | Not affected | |
| 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 | Not affected |
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-2026-123864.