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
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| tillitis | tkeyclient | < 1.3.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | golang-github-tillitis-tkeyclient | 1.3.0-1 | — |
| Debian 13 | golang-github-tillitis-tkeyclient | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | golang-github-tillitis-tkeyclient | No fix yet | — |
| Ubuntu 26.04 LTS | golang-github-tillitis-tkeyclient | No fix yet | — |
| Ubuntu 25.10 | golang-github-tillitis-tkeyclient | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
| openSUSE Leap 15.6 | govulncheck-vulndb | 0.0.20260326T203309-150000.1.155.2 | SUSE-SU-2026:1135-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/tillitis/tkeyclient | < 1.3.0 | 1.3.0 | GHSA-4w7r-3222-8h6v |
Advisories 2
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
- SUSE-SU-2026:1135-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Mar 31, 2026