# CVE-2026-27663: Denial of service in CPCI85 Central Processing/Communication

> Remote attackers can cause denial of service in Siemens CPCI85 and RTUM85 devices by exhausting resources with high-volume requests, requiring a reboot.

- **Severity:** High 7.1 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Mar 2026
- **Updated:** 14 Apr 2026
- **Also known as:** GHSA-j3fp-8j72-vf4g

## What is CVE-2026-27663?

CVE-2026-27663 is a high-severity denial of service vulnerability in Siemens CPCI85 Central Processing/Communication, published on 26 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability has been identified in CPCI85 Central Processing/Communication (All versions < V26.10), RTUM85 RTU Base (All versions < V26.10). The affected application contains denial-of-service (DoS) vulnerability. The remote operation mode is susceptible to a resource exhaustion condition when subjected to a high volume of requests. Sending multiple requests can exhaust resources, preventing parameterization and requiring a reset or reboot to restore functionality.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-27663?


## How do I fix CVE-2026-27663?

No fix has been published for CVE-2026-27663 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-27663 being exploited?

There is no known exploitation of CVE-2026-27663 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27663 and fix it if it is affected.

What it is: CVE-2026-27663 is a high-severity denial of service vulnerability in Siemens CPCI85 Central Processing/Communication, published on 26 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-27663 in the wild and no public exploit code.

Affected product: Siemens CPCI85 Central Processing/Communication. 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-2026-27663/ (Markdown: https://insights.sbomify.com/CVE-2026-27663/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27663
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27663
- OSV: https://osv.dev/vulnerability/CVE-2026-27663

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-27663/
Summaries are generated and may contain mistakes; the official description above is the record.