CVE-2026-121818 (CVSS 7.8)

Description

Herowatch Mini developed by About Time Technologies has a system signing vulnerability. Authenticated local attackers can exploit a publicly available test key to sign malicious programs, allowing them to elevate privileges and execute arbitrary code.

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CVSS v3.1 Score

7.8

HIGH

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

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.03%

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-1394 CWE-1394

References

Other References

https://www.twcert.org.tw/en/cp-139-11362-1e829-2.html https://www.twcert.org.tw/tw/cp-132-11360-ab123-1.html

Frequently Asked Questions

What is CVE-2026-121818? +

Herowatch Mini developed by About Time Technologies has a system signing vulnerability. Authenticated local attackers can exploit a publicly available test key to sign malicious programs, allowing them to elevate privileges and execute arbitrary code. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-121818? +

CVE-2026-121818 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-121818? +

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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