4.7
MEDIUM CVSS 4.0
CVE-2026-32953
Tillitis: TKey Client has an Error in Protocol Implementation
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.

INFO

Published Date :

March 20, 2026, 5:16 a.m.

Last Modified :

March 20, 2026, 5:16 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-32953 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Update TKey Client to version 1.3.0 or later to fix the User Supplied Secret handling bug.
  • Upgrade the TKey Client package to version 1.3.0 or newer.
  • If upgrade is not possible, use USS with hashes not starting with zero byte.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-32953.

URL Resource
https://github.com/tillitis/tkeyclient/commit/4954dccf0287657edf8d405057e134cdff9c59e8
https://github.com/tillitis/tkeyclient/releases/tag/v1.3.0
https://github.com/tillitis/tkeyclient/security/advisories/GHSA-4w7r-3222-8h6v
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-32953 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-32953 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-32953 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-32953 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 20, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-303
    Added Reference https://github.com/tillitis/tkeyclient/commit/4954dccf0287657edf8d405057e134cdff9c59e8
    Added Reference https://github.com/tillitis/tkeyclient/releases/tag/v1.3.0
    Added Reference https://github.com/tillitis/tkeyclient/security/advisories/GHSA-4w7r-3222-8h6v
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.