# CVE-2026-42503: Accidental binding to INADDR_ANY might lead to RCE in golang.org/x/tools/gopls

> Developers using gopls with specific debug flags may inadvertently expose the server to the network, allowing remote code execution.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 May 2026
- **Updated:** 7 May 2026
- **Also known as:** DEBIAN-CVE-2026-42503, GHSA-9344-f92h-vr44, UBUNTU-CVE-2026-42503

## What is CVE-2026-42503?

CVE-2026-42503 is a high-severity vulnerability in golang.org/x/tools/gopls, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

gopls by default communicates via pipe. However, -port and -listen flags are supported as means of debugging.
If -listen is given a value without an explicit host (e.g. :8080), or -port is used, gopls will listen on 0.0.0.0. 
As a result, users might inadvertently cause gopls to bind 0.0.0.0.
This can allow a malicious party on the same network to execute code arbitrarily via gopls.

Weakness: CWE-1327 (Binding to an Unrestricted IP Address)

## Which versions are affected by CVE-2026-42503?

It affects 1 product.


Products: Golang Gopls.

## How do I fix CVE-2026-42503?

Change a configuration setting.

## Is CVE-2026-42503 being exploited?

There is no known exploitation of CVE-2026-42503 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42503 and fix it if it is affected.

What it is: CVE-2026-42503 is a high-severity vulnerability in golang.org/x/tools/gopls, published on 6 May 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-2026-42503 in the wild and no public exploit code.

Affected product: golang.org/x/tools/gopls. 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-2026-42503/ (Markdown: https://insights.sbomify.com/CVE-2026-42503/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42503
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42503
- OSV: https://osv.dev/vulnerability/CVE-2026-42503

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42503/
Summaries are generated and may contain mistakes; the official description above is the record.