CVE-2026-123865 Node.js is vulnerable to an HTTP/2 memory and file-descriptor leak via a protocol error during session shutdown
Unauthenticated HTTP/2 clients can leak Node.js server memory and file descriptors by sending GOAWAY during session shutdown.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Harmful if only installed
- No
- Needs a specific call
- No
- Fix
- Available
What is CVE-2026-123865?
CVE-2026-123865 is a high-severity denial of service vulnerability in nodejs node, published on 11 Nov 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-400
Which versions are affected by CVE-2026-123865?
An affected version is exposed as installed. No special setting or call is needed.
How do I fix CVE-2026-123865?
No fix published yet.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-123865 being exploited?
There is no known exploitation of CVE-2026-123865 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-123865, BELL-CVE-2026-123865, DEBIAN-CVE-2026-123865, GHSA-jj6m-hq7p-qvhr, UBUNTU-CVE-2026-123865.