CVE-2026-78402: Stack Overflow (CVSS 7.8)

Description

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.

Is your site exposed to CVE-2026-78402?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.04%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-121 CWE-121

CWE-787 Out-of-bounds Write

References

Other References

https://supportportal.thalesgroup.com/csm?id=kb_article_view&sys_kb_id=50fc9f3b3b005f10bba8b41864e45a61&sysparm_article=KB0031216

Frequently Asked Questions

What is CVE-2026-78402? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-78402? +

CVE-2026-78402 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-78402? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-101339

A HIP resource record that fills the RDATA near or at is limit, and has another dname RDATA field (a …

CVE-2026-6239

A stack‑based buffer overflow vulnerability exists in Tapo C520WS v2 in the ONVIF CreateUsers service, where the device fails to …

CVE-2026-57161

PJSIP is a free and open source multimedia communication library written in C. Prior to commit acc03b5, a stack buffer …

CVE-2026-8356

LibreOffice can import presentations in the legacy binary PPT format. A stack buffer overflow existed when importing a colour-replacement record. …

CVE-2026-40489

editorconfig-core-c is an EditorConfig core library for use by plugins supporting EditorConfig parsing. Versions up to and including 0.12.10 have …

CVE-2025-26382

Under certain circumstances the iSTAR Configuration Utility (ICU) tool could have a buffer overflow issue

CVE-2026-78402