Critical severity · published Sep 15, 2026
CVE-2026-81855
Wärtsilä FOS-Onboard Use of Hard-coded Cryptographic Key
9.1
CVSS
0.6%
EPSS
No
On KEV
Description
A hardcoded cryptographic client authentication key vulnerability exists in the robot testing framework component of Wärtsilä FOS-Onboard.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FO
FOS-Onboard · Wärtsilä
5.07.0923.01 · source: vendor
In the news
VulnerabilityCritical
Wärtsilä FOS-Onboard
View CSAF
Summary
Successful exploitation of these vulnerabilities could allow an attacker to deliver an unauthorized update, execute code, or extract credentials to allow the attacker to impersonate a privileged client.
The following versions of Wärtsilä FOS-Onboard are affected:
FOS-Onboard 5.07.0923.01 (CVE-2026-78225, CVE-2026-81855)
CVSS
Vendor
Equipment
Vulnerabilities
v3 9.1
Wärtsilä
Wärtsilä FOS-Onboard
Use of Hard-coded Cryptographic Key
Background
Critical Infrastructure Sectors: Transportation Systems
Countries/Areas Deployed: Worldwide
Company Headquarters Location: Finland
Vulnerabilities
Expand All +
CVE-2026-78225
A hardcoded cryptographic server key vulnerability exists in the deployer-ng Update Controller component of Wärtsilä FOS-Onboard.
View CVE Details
Affected Products
Wärtsilä FOS-Onboard
Vendor: Wärtsilä
Product Version: Wärtsilä FOS-Onboard: 5.07.0923.01
Product Status: known_affected
Remediations
Mitigation Wärtsilä states that the vulnerabilities are not exploitable when the product is installed as recommended, and has developed a security patch. Users are also directed to contact Wärtsilä to obtain and install the patch. To obtain and install the latest patch, contact Wärtsilä: https://www.wartsila.com/services-catalogue/engine-services-4-stroke/wartsila-ics-patch-deployment#contact
Relevant CWE: CWE-321 Use...
Sep 15, 2026·CISA Advisories
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-81855
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-81855
github.com
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-258-02.json
www.cisa.gov
https://www.cisa.gov/news-events/ics-advisories/icsa-26-258-02
www.wartsila.com
https://www.wartsila.com/marine/products/data-service-downloads/fos-downloads
More from FOS-Onboard
9.0
CVE-2026-78225
Wärtsilä FOS-Onboard Use of Hard-coded Cryptographic Key
