Vulnerability in Tillitis Tkey Client
CVE-2026-32953
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.
EPSS: 0.002 (15.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Tillitis Tkey_client
- Tillitis Tkeyclient — versions < 1.3.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-32953?
- CVE-2026-32953 is a medium-severity vulnerability in Tillitis Tkey Client, classified under Incorrect Implementation of Authentication Algorithm. CVSS score: 4.6/10. Published 2026-03-20.
- How severe is CVE-2026-32953?
- Medium severity. CVSS v3 base score is 4.6 out of 10.