major vulnerability· requires attention

Affects Wärtsilä FOS-Onboard OT component used in maritime and power systems; allows update spoofing and device takeover — high-impact to critical infrastructure.

OT/ICS

CVE-2026-78225

9.5

Critical

EPSS 0.51%

Hardcoded cryptographic server key in Wärtsilä FOS‑Onboard update controller

exploited

No known exploitation not in CISA KEV as of our last sync

fix

No fixed release stated by the publisher

likelihood

EPSS 0.51%top 57% of scored CVEs

Published 15 Sept 2026Analysed here 18 Sept 2026CVSS scored by the publisher (CNA)

common questions

Is CVE-2026-78225 being exploited?

Not confirmed. CVE-2026-78225 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.51% probability of exploitation in the next 30 days.

How severe is CVE-2026-78225?

CVE-2026-78225 is rated Critical with a CVSS score of 9.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2026-78225?

Not known from our data. No patch reference has been recorded for CVE-2026-78225, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.

What does CVE-2026-78225 affect?

CVE-2026-78225 affects Wärtsilä FOS-Onboard (deployer-ng Update Controller). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-78225?

Isolate devices, block update/management ports, contact Wärtsilä and apply vendor patch when released

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary

technical analysis

affected

Wärtsilä FOS-Onboard (deployer-ng Update Controller)

impact

Attacker can impersonate update server, decrypt/forge updates, push malicious firmware leading to remote code execution and device takeover.

action required

Immediate action required

affected versions

Wärtsilä FOS-Onboard

affected5.07.0923.01

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

cisa ssvc

exploitation: none
automatable: no
technical impact: total

Assessed by CISA 16 Sept 2026 (SSVC 2.0.3).

timeline

15 Sept 2026Published
16 Sept 2026CISA SSVC assessment: exploitation none · 1 day later
18 Sept 2026Analysed by vulneraibility.com · 2 days later
24 Sept 2026CVE record last updated · 6 days later

how to fix

Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.

references

NVD CVE.org CVE Details Source

3 references in the CVE record: 3 links

Linkwartsila.com /marine/products/data-service-downloads/fos-downloads
Linkcisa.gov /news-events/ics-advisories/icsa-26-258-02
Linkgithub.com /cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-258-02.json

sources

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
CISA Vulnrichment (ADP): SSVC decision points
FIRST EPSS: exploit probability and percentile
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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