# CVE-2026-57999: luci-app-tailscale-community - Command Injection via tailscale.do_login RPC

> Authenticated attackers can execute arbitrary commands as root via improper quoting in the Tailscale login RPC method.

- **Severity:** High 7.7 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **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:** 29 Jun 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-qr7m-7592-rcvx, GHSA-xwc5-mx58-rh35

## What is CVE-2026-57999?

CVE-2026-57999 is a high-severity command injection vulnerability in openwrt luci-app-tailscale-community, published on 29 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

luci-app-tailscale-community contains a command injection vulnerability in the tailscale.do_login RPC method that allows authenticated users to execute arbitrary commands as root. The vulnerability exists because user-controlled loginserver and loginserver_authkey parameters are improperly quoted within a double-quoted shell command, allowing shell substitutions like $() to be evaluated by the outer shell before argument processing.

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

## Which versions are affected by CVE-2026-57999?


## How do I fix CVE-2026-57999?

No fix has been published for CVE-2026-57999 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57999 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57999 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57999 and fix it if it is affected.

What it is: CVE-2026-57999 is a high-severity command injection vulnerability in openwrt luci-app-tailscale-community, published on 29 Jun 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-2026-57999 exists.

Affected product: openwrt luci-app-tailscale-community. 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-2026-57999/ (Markdown: https://insights.sbomify.com/CVE-2026-57999/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57999
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57999
- OSV: https://osv.dev/vulnerability/CVE-2026-57999

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57999/
Summaries are generated and may contain mistakes; the official description above is the record.