# CVE-2026-18397: SConnect: Native Host Unauthenticated Remote Code Execution Vulnerability

> Unauthenticated attackers can execute arbitrary code on victim machines via the SConnect native host messaging interface.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **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:** 1 Oct 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-cq27-3937-pqqv

## What is CVE-2026-18397?

CVE-2026-18397 is a critical code injection vulnerability in Thales SConnect, published on 1 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

This vulnerability enables unauthenticated remote code execution (RCE) on a victim's machine by exploiting a combination of cryptographic weaknesses and memory management issues in the SConnect native host component.

The attack leverages an unrestricted messaging interface between an attacker-controlled web page and the native host, allowing malicious input to bypass security checks.

Weakness: CWE-457 (Use of Uninitialized Variable), CWE-347 (Improper Verification of Cryptographic Signature), CWE-252 (Unchecked Return Value), CWE-130 (Improper Handling of Length Parameter Inconsistency)

## Which versions are affected by CVE-2026-18397?


## How do I fix CVE-2026-18397?

No fix has been published for CVE-2026-18397 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18397 being exploited?

There is no known exploitation of CVE-2026-18397 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18397 and fix it if it is affected.

What it is: CVE-2026-18397 is a critical code injection vulnerability in Thales SConnect, published on 1 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-2026-18397 in the wild and no public exploit code.

Affected product: Thales SConnect. 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-2026-18397/ (Markdown: https://insights.sbomify.com/CVE-2026-18397/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18397
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18397
- OSV: https://osv.dev/vulnerability/CVE-2026-18397

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18397/
Summaries are generated and may contain mistakes; the official description above is the record.