9.8
CRITICAL CVSS 3.1
CVE-2026-78403
Unauthenticated Stack Buffer Overflow in Sentinel Keys Server
Description

Stack-based buffer overflow and missing authorization 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 HTTP request. An attacker may craft an HTTP request and send it to Sentinel Keys Server. It may lead to remote code execution as NT AUTHORITY\SYSTEM. This issue affects Sentinel Keys Server: versions lower than 1.3.8.0.

INFO

Published Date :

Oct. 30, 2026, 8:17 p.m.

Last Modified :

Oct. 30, 2026, 8:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-78403 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Thalesgroup sentinel_keys_server
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL 9d5917ae-205d-4ae5-8749-1f49479b1395
CVSS 3.1 CRITICAL MITRE-CVE
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL 9d5917ae-205d-4ae5-8749-1f49479b1395
CVSS 4.0 CRITICAL [email protected]
Solution
Update Sentinel Keys Server to version 1.3.8.0 or later to fix buffer overflow and authorization.
  • Update Sentinel Keys Server to version 1.3.8.0.
  • Apply vendor-provided security patches.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-78403.

URL Resource
https://supportportal.thalesgroup.com/csm?id=kb_article_view&sys_kb_id=50fc9f3b3b005f10bba8b41864e45a61&sysparm_article=KB0031216
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-78403 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-78403 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-78403 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-78403 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 30, 2026

    Action Type Old Value New Value
    Added Description Stack-based buffer overflow and missing authorization 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 HTTP request. An attacker may craft an HTTP request and send it to Sentinel Keys Server. It may lead to remote code execution as NT AUTHORITY\SYSTEM. This issue affects Sentinel Keys Server: versions lower than 1.3.8.0.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-121
    Added CWE CWE-862
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/78xxx/CVE-2026-78403.json">CVE-2026-78403</a>
    Added Reference https://supportportal.thalesgroup.com/csm?id=kb_article_view&sys_kb_id=50fc9f3b3b005f10bba8b41864e45a61&sysparm_article=KB0031216
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 30, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-78403', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-30T19:59:29.771309Z'}
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.