CVE-2026-63406 AnyCable: Telemetry Subsystem Contains Hardcoded Authentication Token and Transmits CLI Arguments Including Secrets
The telemetry subsystem uses a hardcoded authentication token and transmits CLI arguments containing secrets, potentially exposing sensitive configuration data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-63406?
CVE-2026-63406 is a medium-severity vulnerability in anycable, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
AnyCable is a realtime server for reliable two-way communication that supports any backend. Prior to 1.6.15, the telemetry subsystem in telemetry/config.go enables tracking with a hardcoded public authToken, while clusterFingerprint in telemetry/telemetry.go reads the full configuration file and raw os.Args returned by anycableCLIArgs, including values supplied through --secret, --jwt_secret, and --http_rpc_secret. These inputs are passed to generateDigest, where sha256.New produces the hexadecimal fingerprint that is sent as telemetry. The available source therefore does not show raw credentials leaving the process or establish the advisory's claimed confidentiality loss, although the stable fingerprint is derived from secret-bearing configuration and the default telemetry client uses publicly known authentication material. This issue is fixed in version 1.6.15.
Which versions are affected by CVE-2026-63406?
3 open source packages ship an affected version, including github.com/anycable/anycable and github.com/anycable/anycable-go.
| Package | Affected | Fixed in |
|---|---|---|
github.com/anycable/anycable Go | All versions | 1.6.15 |
github.com/anycable/anycable Go | All versions | 1.6.15 |
github.com/anycable/anycable-go Go | All versions | None |
How do I fix CVE-2026-63406?
Upgrade github.com/anycable/anycable to 1.6.15 or later.
Is CVE-2026-63406 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63406 exists.
Sources
Also known as GHSA-w72w-9qmj-c9qm, GO-2026-6529.