# CVE-2026-123871: Node.js is vulnerable to proxy credential disclosure via ERR_PROXY_INVALID_CONFIG error messages

> Node.js error messages can leak proxy credentials to logs and crash reports, exposing secrets to anyone reading them.

- **Severity:** Medium 6.2 (`CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Harmful if only installed:** No
- **Needs a specific call:** No
- **Fix available:** Yes
- **Published:** 11 Nov 2026
- **Updated:** 11 Nov 2026
- **Also known as:** ALPINE-CVE-2026-123871, BELL-CVE-2026-123871, DEBIAN-CVE-2026-123871, GHSA-8669-428h-mj7x, UBUNTU-CVE-2026-123871

## What is CVE-2026-123871?

CVE-2026-123871 is a medium-severity information disclosure vulnerability in nodejs node, published on 11 Nov 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Node.js discloses proxy credentials in ERR_PROXY_INVALID_CONFIG error messages. CVE-2026-48615 established that a proxy credential must not appear in a Node.js error message and redacted the username and password from ProxyConfig.href, but that fix missed four error paths in the same subsystem, one of them inside the same constructor, which interpolate the raw proxy URL, credentials included, into an ERR_PROXY_INVALID_CONFIG message. The proxy URL comes from the environment, but the defect is the sink: a secret that Node.js redacts everywhere else is emitted verbatim into a much wider audience than the process environment, such as stderr, container logs, log aggregation, and crash reporting services. This vulnerability affects Node.js 26.x, 24.x, and 22.x.

Weakness: CWE-209 (Generation of Error Message Containing Sensitive Information)

## Which versions are affected by CVE-2026-123871?

An affected version is exposed as installed. No special setting or call is needed.


## How do I fix CVE-2026-123871?

No fix published yet.

## Is CVE-2026-123871 being exploited?

There is no known exploitation of CVE-2026-123871 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123871 and fix it if it is affected.

What it is: CVE-2026-123871 is a medium-severity information disclosure vulnerability in nodejs node, published on 11 Nov 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-123871 in the wild and no public exploit code.
Exposure: An affected version is exposed as installed. No special setting or call is needed.

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.
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-2026-123871/ (Markdown: https://insights.sbomify.com/CVE-2026-123871/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123871
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123871
- OSV: https://osv.dev/vulnerability/CVE-2026-123871

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123871/
Summaries are generated and may contain mistakes; the official description above is the record.