# CVE-2026-23759: Perle IOLAN STS/SCS Authenticated Command Injection via 'shell ps'

> Authenticated attackers can inject commands via the 'ps' command in Perle IOLAN terminal servers to execute arbitrary code with root privileges.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Mar 2026
- **Updated:** 14 May 2026
- **Also known as:** GHSA-rcw4-cmhr-ggx7

## What is CVE-2026-23759?

CVE-2026-23759 is a high-severity command injection vulnerability in Perle Systems IOLAN SCS, published on 17 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Perle IOLAN STS/SCS terminal server models with firmware versions prior to 6.0 allow authenticated OS command injection via the restricted shell accessed over Telnet or SSH. The shell 'ps' command does not perform proper argument sanitization and passes user-supplied parameters into an 'sh -c' invocation running as root. An authenticated attacker who can log in to the device can inject shell metacharacters after the 'ps' subcommand to execute arbitrary OS commands with root privileges, leading to full compromise of the underlying operating system.

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

## Which versions are affected by CVE-2026-23759?


## How do I fix CVE-2026-23759?

No fix has been published for CVE-2026-23759 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-23759 being exploited?

There is no known exploitation of CVE-2026-23759 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23759 and fix it if it is affected.

What it is: CVE-2026-23759 is a high-severity command injection vulnerability in Perle Systems IOLAN SCS, published on 17 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23759 in the wild and no public exploit code.

Affected product: Perle Systems IOLAN SCS. 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-2026-23759/ (Markdown: https://insights.sbomify.com/CVE-2026-23759/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23759
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23759
- OSV: https://osv.dev/vulnerability/CVE-2026-23759

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23759/
Summaries are generated and may contain mistakes; the official description above is the record.