# 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.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-w72w-9qmj-c9qm, GO-2026-6529

## 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.

Weakness: CWE-798 (Use of Hard-coded Credentials), CWE-312 (Cleartext Storage of Sensitive Information)

## 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 | Ecosystem | 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63406 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63406 exists.

Affected packages and fixed versions:
- github.com/anycable/anycable (Go): affected all versions; fixed in 1.6.15
- github.com/anycable/anycable (Go): affected all versions; fixed in 1.6.15
- github.com/anycable/anycable-go (Go): affected all versions; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-63406/ (Markdown: https://insights.sbomify.com/CVE-2026-63406/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63406
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63406
- OSV: https://osv.dev/vulnerability/CVE-2026-63406

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63406/
Summaries are generated and may contain mistakes; the official description above is the record.