CVE-2026-78239: Missing Auth (CVSS 9.8)

Description

Xiiaozet LK100W exposes a critical management function that can be invoked without authentication, allowing a remote attacker to enable administrative services that should be restricted. Successful exploitation may permit unauthorized access to the device.

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CVSS v3.1 Score

9.8

CRITICAL

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

EPSS — Exploit Prediction

0.0055

Probability of exploitation

0.45%

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-306 Missing Authentication

References

Other References

https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-239-01.json https://www.cisa.gov/news-events/ics-advisories/icsa-26-239-01

Frequently Asked Questions

What is CVE-2026-78239? +

Xiiaozet LK100W exposes a critical management function that can be invoked without authentication, allowing a remote attacker to enable administrative services that should be restricted. Successful exploitation may permit unauthorized access to the device. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-78239? +

CVE-2026-78239 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0055, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-78239? +

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.

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