# CVE-2026-71243: backmeup (npm) - OS Command Injection via Backup Option Values

> Attackers can execute arbitrary OS commands by injecting malicious characters into backup option values in the backmeup npm package.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 5 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-c6xg-rfqh-85cp

## What is CVE-2026-71243?

CVE-2026-71243 is a high-severity command injection vulnerability in adaltas backmeup, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The backmeup npm package assembles shell command strings by directly concatenating its option values (name, source, destination, filter) - e.g. cmd = "mkdir -p " + path.join(info.destination, info.name) + "; " - and executes the resulting string through a shell via ssh2-exec (locally via child_process, or remotely via SSH when an ssh handle is supplied), rather than using execFile/spawn with an argument array.

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

## Which versions are affected by CVE-2026-71243?


## How do I fix CVE-2026-71243?

No fix has been published for CVE-2026-71243 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-71243 being exploited?

There is no known exploitation of CVE-2026-71243 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71243 and fix it if it is affected.

What it is: CVE-2026-71243 is a high-severity command injection vulnerability in adaltas backmeup, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-71243 in the wild and no public exploit code.

Affected product: adaltas backmeup. 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-2026-71243/ (Markdown: https://insights.sbomify.com/CVE-2026-71243/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71243
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71243
- OSV: https://osv.dev/vulnerability/CVE-2026-71243

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-71243/
Summaries are generated and may contain mistakes; the official description above is the record.