# CVE-2026-102073: Integer overflow in APOGEE MBC (PPC) (BACnet)

> Unauthenticated attackers can exploit an integer overflow in the web service to read device memory or cause denial of service in Siemens building automation controllers.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-3jcw-mhf3-39cw

## What is CVE-2026-102073?

CVE-2026-102073 is a high-severity vulnerability in Siemens APOGEE MBC (PPC) (BACnet), published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BACnet) (All versions), APOGEE MEC (PPC) (P2 Ethernet) (All versions), APOGEE PXC Compact (BACnet) (All versions < V3.5.7), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.21), APOGEE PXC Modular (BACnet) (All versions < V3.5.7), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.21), TALON TC Compact (BACnet) (All versions < V3.5.7), TALON TC Modular (BACnet) (All versions < V3.5.7). The affected product web service does not properly validate the length of user-controllable input. This could allow an unauthenticated remote attacker to read portions of device memory or to cause a denial-of-service condition.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2026-102073?


## How do I fix CVE-2026-102073?

No fix has been published for CVE-2026-102073 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-102073 being exploited?

There is no known exploitation of CVE-2026-102073 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102073 and fix it if it is affected.

What it is: CVE-2026-102073 is a high-severity vulnerability in Siemens APOGEE MBC (PPC) (BACnet), published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-102073 in the wild and no public exploit code.

Affected product: Siemens APOGEE MBC (PPC) (BACnet). 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-2026-102073/ (Markdown: https://insights.sbomify.com/CVE-2026-102073/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102073
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102073
- OSV: https://osv.dev/vulnerability/CVE-2026-102073

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-102073/
Summaries are generated and may contain mistakes; the official description above is the record.