# CVE-2026-123875: Null dereference in node

> Unauthenticated clients can crash Node.js HTTP/2 servers serving files by cancelling file downloads.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **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:** Yes (`respondWithFile()`, `stream.respondWithFile()`, `stream.respondWithFD()`)
- **Fix available:** Yes
- **Published:** 11 Nov 2026
- **Updated:** 11 Nov 2026
- **Also known as:** ALPINE-CVE-2026-123875, BELL-CVE-2026-123875, DEBIAN-CVE-2026-123875, GHSA-v6qh-ch8g-j833, UBUNTU-CVE-2026-123875

## What is CVE-2026-123875?

CVE-2026-123875 is a medium-severity null pointer dereference 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

A NULL pointer dereference in Node.js HTTP/2 lets an unauthenticated client crash the server, over both TLS and cleartext, by cancelling file downloads. When the server serves a file with stream.respondWithFile() or stream.respondWithFD() and the client cancels the request, a StreamPipe used for the transfer is torn down in an order that leaves a NULL pointer which is then dereferenced, aborting the process. No crafted frames are needed, and a handful of cancelled requests against a default file-serving handler is enough. This vulnerability affects Node.js 26.x, 24.x, and 22.x.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-123875?

An affected version is only exploitable if your software calls respondWithFile(), stream.respondWithFile() or stream.respondWithFD(). Many projects that include it are not exposed.


## How do I fix CVE-2026-123875?

No fix published yet.

## Is CVE-2026-123875 being exploited?

There is no known exploitation of CVE-2026-123875 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123875 and fix it if it is affected.

What it is: CVE-2026-123875 is a medium-severity null pointer dereference 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.
Exploitation: There is no known exploitation of CVE-2026-123875 in the wild and no public exploit code.
Exposure: An affected version is only exploitable if your software calls respondWithFile(), stream.respondWithFile() or stream.respondWithFD(). Many projects that include it are not exposed.

Affected product: nodejs node. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
   If an affected version is present, also search the code for calls to respondWithFile(), stream.respondWithFile() or stream.respondWithFD() and report whether any exist.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-123875/ (Markdown: https://insights.sbomify.com/CVE-2026-123875/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123875
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123875
- OSV: https://osv.dev/vulnerability/CVE-2026-123875

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123875/
Summaries are generated and may contain mistakes; the official description above is the record.