---
id: "CVE-2026-78402"
kind: "vulnerability"
aliases: ["CVE-2026-78402"]
title: "Thales Sentinel Keys Server: buffer overflow lets local users gain SYSTEM rights"
severity: "high"
cvss: 7.8
epss: null
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["sentinel-keys-server", "thales", "vendor", "windows"]
not_affected_if: ["version-1.3.8.0-or-later"]
published_at: "2026-10-30T20:17:17+00:00"
first_seen_at: "2026-10-30T20:25:39+00:00"
updated_at: "2026-10-30T20:26:27+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-78402", "first_seen_at": "2026-10-30T20:25:39+00:00"}]
---

# Thales Sentinel Keys Server: buffer overflow lets local users gain SYSTEM rights

Thales Sentinel Keys Server on Windows does not check the length of the first field in incoming messages, causing a stack-based buffer overflow and out-of-bounds write. A local attacker who sends a crafted message can run code as NT AUTHORITY\SYSTEM.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Sentinel Keys Server version on the Windows host, comparing it against `1.3.8.0`.

## Fix

- Sentinel Keys Server: move to `1.3.8.0` or later.

## Timeline

- 2026-10-30T20:25:39+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-78402

## From the sources

Stack-based buffer overflow and out-of-bounds
write vulnerability in Thales Sentinel Keys Server on Windows allows Overflow
Buffers. 



Sentinel Keys Server does not check the length of the first field in
the input message. A local attacker may craft an input and send it to Sentinel
Keys Server. It may lead to code execution as NT AUTHORITY\SYSTEM enabling
local privilege escalation.





This issue affects Sentinel Keys Server: versions
lower than 1.3.8.0.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_