CVE-2026-32953CWE-303

Tillitis: TKey Client has an Error in Protocol Implementation

Medium · published March 20, 2026

CVSS v4.0
4.7
EPSS
0%
Percentile
12.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
4.7 · MEDIUM
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
EPSS
0.00225 · 12.5th percentile
Weakness
CWE-303 · Incorrect Implementation of Authentication Algorithm
Published
2026-03-20T04:24Z
EPSS history
Timeline
  • 20 MAR 04:24Z
    Tillitis: TKey Client has an Error in Protocol Implementation
    cvelistv5