# CVE-2026-18787: GL.iNet AX1800 RPC Endpoint oui-rpc.lua remove_rule command injection

> Remote attackers can execute arbitrary commands on GL.iNet AX1800 routers via the RPC endpoint, requiring immediate firmware updates.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Aug 2026
- **Updated:** 4 Aug 2026
- **Also known as:** GHSA-vfp6-456q-5pqw

## What is CVE-2026-18787?

CVE-2026-18787 is a high-severity command injection vulnerability in GL.iNet AX1800, published on 4 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was identified in GL.iNet AX1800 up to 4.8.3. The affected element is the function remove_rule of the file /usr/share/gl-ngx/oui-rpc.lua of the component RPC Endpoint. The manipulation of the argument args.id leads to command injection. The attack is possible to be carried out remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure.

Weakness: CWE-77 (Improper Neutralization of Special Elements used in a Command), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2026-18787?


## How do I fix CVE-2026-18787?

No fix has been published for CVE-2026-18787 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18787 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18787 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18787 and fix it if it is affected.

What it is: CVE-2026-18787 is a high-severity command injection vulnerability in GL.iNet AX1800, published on 4 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-18787 exists.

Affected product: GL.iNet AX1800. 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-2026-18787/ (Markdown: https://insights.sbomify.com/CVE-2026-18787/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18787
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18787
- OSV: https://osv.dev/vulnerability/CVE-2026-18787

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18787/
Summaries are generated and may contain mistakes; the official description above is the record.