# CVE-2026-121817: About Time Technologies｜Herowatch Go Server - Insecure Direct Object Reference

Status: published. Published: 2026-11-04. Updated: 2026-11-04.

Herowatch Go Server developed by About Time Technologies has a Insecure Direct Object Reference vulnerability. Authenticated remote attackers can modify specific parameters to access or operate other users' data and functions.

## Remediation

- fix: The product is no longer maintained. Users are advised to replace it with a supported device. (source: CNA: twcert)

## Affected products and versions

- About Time Technologies / Herowatch Go Server: all (affected, custom). Source: CNA: twcert

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N; source: CNA: twcert

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N; source: CNA: twcert

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-639

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://www.twcert.org.tw/en/cp-139-11364-0dce6-2.html (CNA: twcert; third-party-advisory)

- https://www.twcert.org.tw/tw/cp-132-11366-d92ac-1.html (CNA: twcert; third-party-advisory)

## Provenance

- CNA: twcert: https://www.cve.org/CVERecord?id=CVE-2026-121817; retrieved 2026-11-04; source updated 2026-11-04

Revision: cf534b5509b443265fc5aefcc23b0adcd5ef285e555c825b688a1400058973d6

Canonical: https://y2.dev/cve/CVE-2026-121817

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