# CVE-2026-32953

## Summary

- **CVE ID:** CVE-2026-32953
- **Severity:** MEDIUM
- **CVSS Score:** 4.7 (CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:H)
- **CWE:** CWE-303
- **Published:** Mar 20, 2026
- **Last Modified:** Mar 20, 2026

## Description

Tillitis TKey Client package is a Go package for a TKey client. Versions 1.2.0 and below contain a critical bug in the tkeyclient Go module which causes 1 out of every 256 User Supplied Secrets (USS) to be silently ignored, producing the same Compound Device Identifier (CDI)—and thus the same key material—as if no USS is provided. This happens because a buffer index error overwrites the USS-enabled boolean with the first byte of the USS digest, so any USS whose hash starts with 0x00 is effectively discarded. This issue has been fixed in version 1.3.0. Users unable to upgrade immediately should switch to a USS whose hash does not begin with a zero byte.

## Affected Products

- tillitis — tkeyclient (< 1.3.0)

## References

- [CNA](https://github.com/tillitis/tkeyclient/security/advisories/GHSA-4w7r-3222-8h6v)
- [CNA](https://github.com/tillitis/tkeyclient/commit/4954dccf0287657edf8d405057e134cdff9c59e8)
- [CNA](https://github.com/tillitis/tkeyclient/releases/tag/v1.3.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.25%
- **EPSS Percentile:** 15.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._