CVE
Node.js is vulnerable to an HTTP/2 memory and file-descriptor leak via a protocol error during session shutdown
Affects Node.js HTTP/2 servers on releases before 22.23.5, from 23.0.0 to before 24.22.3, and from 25.0.0 to before 26.13.1. The fix is in 22.23.5, 24.22.3, and 26.13.1.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 22.23.5, 24.22.3, 26.13.1
- Who is exposed
- Default setups
Do first: Check every install: default setups are affected.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 47/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Default setups
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Node.js HTTP/2 servers can be made to leak memory and file descriptors until they run out of resources. An unauthenticated remote client can trigger this by starting a session shutdown and then sending a protocol error during it, and the leak is permanent for each affected connection.
Read the original description
An unauthenticated HTTP/2 client can permanently leak Node.js server memory and file descriptors. If a peer triggers a protocol error, for example an oversized frame header, while the session is already shutting down, nghttp2 tears the session down internally but Node.js never notices, leaving a dangling session: the socket stays in CLOSE_WAIT and all of Node.js's HTTP/2 state for that connection is held in memory indefinitely, with no further cost to the attacker. The attacker can start the shutdown remotely by sending GOAWAY(NO_ERROR), so it is reliable against default HTTP/2 servers. It is an incomplete-fix case of CVE-2026-48937: that fix detected nghttp2 internal terminations by watching for GOAWAY sent while not shutting down, but missed terminations that arrive while the session is already shutting down. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Who should check
Teams running Node.js 22.x, 24.x or 26.x HTTP/2 servers, such as Node.js services that accept HTTP/2 clients
Read the source excerpt
“This vulnerability affects all users in active release lines: 22.x, 24.x, 26.x”
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure22/25Default setups, reachable over the network without a login
- Reach17/20Affects Node.js (a widely deployed server, runtime, framework or database)
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 87 if added to CISA KEV
- Would score about 82 if CISA's SSVC rates exploitation active
What to do
Check every install: default setups are affected.
Upgrade to a fixed version: 22.23.5, 24.22.3, 26.13.1.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-123865 (Node.js is vulnerable to an HTTP/2 memory and file-descriptor leak via a protocol error during session shutdown), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-123865 (entry last updated 2026-11-11):
Affected:
- nodejs node: from 0.0.0, fixed in 22.23.5; from 23.0.0, fixed in 24.22.3; from 25.0.0, fixed in 26.13.1
Fixed versions: 22.23.5, 24.22.3, 26.13.1.
Conditions (all must be true for the bug to be hit):
- The HTTP/2 session is already shutting down when the protocol error arrives (source: https://nodejs.org/en/blog/vulnerability/november-2026-security-releases)
- The attacker starts the shutdown by sending GOAWAY(NO_ERROR) (source: https://nodejs.org/en/blog/vulnerability/november-2026-security-releases)
Setup: the bug is reachable in a default setup; no special feature or setting is needed.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-123865 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-123865 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases
- https://cna.openjsf.org/security-advisories.html
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-123865
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-123865"}.Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- nodejs node
From 0.0.0 · fixed in 22.23.5; From 23.0.0 · fixed in 24.22.3; From 25.0.0 · fixed in 26.13.1
Evidence 4
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 1
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123865
Is CVE-2026-123865 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A remote, unauthenticated HTTP/2 client can permanently leak Node.js server memory and file descriptors. The leak happens when a protocol error arrives while the HTTP/2 session is already shutting down, and the shutdown can be started by sending GOAWAY(NO_ERROR).Source: nodejs.org
Which versions are affected by CVE-2026-123865?
node: from 0.0.0 before 22.23.5; from 23.0.0 before 24.22.3; from 25.0.0 before 26.13.1.Source: cve.now feed data
Am I affected, and how do I check?
Affected Node.js versions are those before 22.23.5, from 23.0.0 through 24.22.2, and from 25.0.0 through 26.13.0. The affected setup is an HTTP/2 session that is shutting down when a protocol error arrives. Check the installed version with node --version.Source: nodejs.org
How do I fix CVE-2026-123865?
Upgrade to 22.23.5, 24.22.3, or 26.13.1, matching the release line in use. The advisory lists these as the fixed versions for each range.Source: nodejs.org