# CVE-2026-63357: Cross-site scripting in SIMATIC Drive Controller CPU 1504D TF

> Attackers can execute arbitrary JavaScript in a user's browser via crafted files, enabling unauthorized PLC operations within the user's authorization scope.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-7372-jr4h-6q2x

## What is CVE-2026-63357?

CVE-2026-63357 is a medium-severity cross-site scripting vulnerability in Siemens SIMATIC Drive Controller CPU 1504D TF, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Affected devices do not properly sanitize calculated signal data contained in imported calculated signal files before rendering it on the Trace page.

This could allow an attacker to social engineer an authorized user who holds the function right “Read diagnostics” into importing a specially crafted file. Successful exploitation could allow attacker-controlled JavaScript to execute in the user’s browser session and perform PLC operations through the web server within the scope of the user’s authorization.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-63357?


## How do I fix CVE-2026-63357?

No fix has been published for CVE-2026-63357 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-63357 being exploited?

There is no known exploitation of CVE-2026-63357 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63357 and fix it if it is affected.

What it is: CVE-2026-63357 is a medium-severity cross-site scripting vulnerability in Siemens SIMATIC Drive Controller CPU 1504D TF, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-63357 in the wild and no public exploit code.

Affected product: Siemens SIMATIC Drive Controller CPU 1504D TF. 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-2026-63357/ (Markdown: https://insights.sbomify.com/CVE-2026-63357/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63357
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63357
- OSV: https://osv.dev/vulnerability/CVE-2026-63357

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-63357/
Summaries are generated and may contain mistakes; the official description above is the record.