CVE-2026-78403: Thalesgroup Sentinel Keys Server · Stack-based Buffer Overflow
Affects Thalesgroup Sentinel Keys ServerSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical : upgrade to 1.3.8.0 as a priority.
Data as of 30 Oct 2026, 20:41 UTC
Thin evidence
One scorer or none| CNA (THA-PSIRT) | CVSS 4.0 | 9.3 |
|---|---|---|
| CNA (THA-PSIRT) | CVSS 3.1 | 9.8 |
- Patch
- Available – fixed in 1.3.8.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade Thalesgroup Sentinel Keys Server to 1.3.8.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ThalesgroupSentinel Keys Server | Affected
| Fixed in
|
AI-suggested
A fixed version 1.3.8.0 of Sentinel Keys Server is available and should be applied to remediate this vulnerability. Users should upgrade to version 1.3.8.0 or later to eliminate the risk of exploitation. No other mitigation or temporary workaround is indicated in the provided data.
Description
CVE-2026-78403 is a critical stack-based buffer overflow and missing authorization vulnerability in Thalesgroup Sentinel Keys Server on Windows. The vulnerability arises because the server does not validate the length of the first field in an HTTP request. An attacker can exploit this flaw by sending a crafted HTTP request, potentially leading to remote code execution with NT AUTHORITY\SYSTEM privileges. This affects Sentinel Keys Server versions prior to 1.3.8.0.