# CVE-2026-15511: Comfast CF-WR631AX V3 FastCGI Backend webmgnt system_wl_upload_pic_file os command injection

> Remote attackers can execute arbitrary OS commands via the filename argument in the webmgnt FastCGI backend of Comfast CF-WR631AX V3 routers.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-hpmx-855m-f9m5

## What is CVE-2026-15511?

CVE-2026-15511 is a critical command injection vulnerability in Comfast CF-WR631AX V3, published on 12 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was determined in Comfast CF-WR631AX V3 up to 2.7.0.8. Affected by this vulnerability is the function system_wl_upload_pic_file of the file /usr/bin/webmgnt of the component FastCGI Backend. This manipulation of the argument filename causes os command injection. It is possible to initiate the attack remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-77 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2026-15511?


## How do I fix CVE-2026-15511?

No fix has been published for CVE-2026-15511 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15511 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15511 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15511 and fix it if it is affected.

What it is: CVE-2026-15511 is a critical command injection vulnerability in Comfast CF-WR631AX V3, published on 12 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15511 exists.

Affected product: Comfast CF-WR631AX V3. 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-2026-15511/ (Markdown: https://insights.sbomify.com/CVE-2026-15511/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15511
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15511
- OSV: https://osv.dev/vulnerability/CVE-2026-15511

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15511/
Summaries are generated and may contain mistakes; the official description above is the record.