CVE-2026-25939: FUXA Unauthenticated Remote Arbitrary Scheduler Write

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.9%, percentile 60: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 60% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes fuxa-server (npm) >= 1.2.8, < 1.2.11, fixed in 1.2.11. Check your lockfile, including transitive dependencies.

What it is

FUXA is a web-based Process Visualization (SCADA/HMI/Dashboard) software. From 1.2.8 through version 1.2.10, an authorization bypass vulnerability in the FUXA allows an unauthenticated, remote attacker to create and modify arbitrary schedulers, exposing connected ICS/SCADA environments to follow-on actions. This has been patched in FUXA version 1.2.11.

From the GitHub advisory

Summary An authorization bypass vulnerability in the FUXA allows an unauthenticated, remote attacker to create and modify arbitrary schedulers, exposing connected ICS/SCADA environments to follow-on actions. This vulnerability affects FUXA version 1.2.8 through version 1.2.10. This has been patched in FUXA version 1.2.11.

Impact This affects all deployments, including those with runtime.settings.secureEnabled set to true.

Exploitation allows an unauthenticated, remote attacker to automatically authenticate as guest and create, modify or delete schedules. These schedules can be configured to trigger immediately or cyclically, forcing connected devices to specific states or values, or executing existing scripts on the server.

Patches

This issue has been patched in FUXA version 1.2.11. Users are strongly encouraged to update to the latest available release.

Weakness type: CWE-862.

Product: fuxa-server (npm) · Assigned by: GitHub_M · Published: 2026-02-09

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.94% probability of exploitation activity in the next 30 days; percentile 60.

Timeline

• 2026-02-09 — CVE record published by GitHub_M
• 2026-02-10 — GitHub-reviewed advisory GHSA-c869-jx4c-q5fc published (critical)
• 2026-02-11 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-c869-jx4c-q5fc github.com
2. CVE.org record CVE-2026-25939 cve.org
3. NVD entry CVE-2026-25939 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com
5. github.com github.com

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