CVE-2026-32953 MEDIUM

CVE-2026-32953: Tillitis: TKey Client has an Error in Protocol Implementation

Vendor Tillitis
Product tkeyclient
Weakness CWE-303
Published March 20, 2026
Last update March 20, 2026

CVSS base score

4.7/10
Attack vector Physical
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 20, 2026 CVE published
March 20, 2026 Record updated