---
id: CVE-2026-59891
aliases:
  - GHSA-pf56-329r-95rw
title: >-
  Credential confusion in @sigstore/oci can leak registry credentials to an
  attacker-controlled registry
summary: >-
  Credential confusion in @sigstore/oci can leak registry credentials to an
  attacker-controlled registry
severity: critical
cvss: 9.6
cwe:
  - CWE-522
vendor: sigstore
product: '@sigstore/oci'
ecosystem: npm
affected:
  - '@sigstore/oci < 0.7.1'
patched:
  - '@sigstore/oci 0.7.1'
published: '2026-07-21'
updated: '2026-07-21'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-pf56-329r-95rw'
references:
  - url: >-
      https://github.com/sigstore/sigstore-js/security/advisories/GHSA-pf56-329r-95rw
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59891'
  - url: >-
      https://github.com/sigstore/sigstore-js/commit/85c58380758b97ce1b74ef470e55cc21f9d3aa89
  - url: >-
      https://github.com/sigstore/sigstore-js/releases/tag/%40sigstore%2Foci%400.7.1
  - url: 'https://github.com/advisories/GHSA-pf56-329r-95rw'
tags:
  - ghsa
  - npm
  - exploit-available
epss: 0.00473
epssPercentile: 0.38343
ingestedAt: '2026-07-21T19:53:40.023Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/gyubin02/cve-2026-59891-control-lab'
  checkedAt: '2026-09-26T09:05:52.933Z'
exploitAvailable: true
---

## Overview

### Impact

This is a credential-exposure / credential-confusion issue.

`getRegistryCredentials()` reads credentials from the Docker config file (`~/.docker/config.json`) and selects an entry by checking whether any configured auth key **contains** the target registry string:

```js
Object.keys(dockerConfig.auths || {}).find((key) => key.includes(registry))
```

Because this is a **substring match rather than an exact host match**, credentials configured for one registry can be selected for — and transmitted to — a *different* registry whose hostname has a substring relationship with a configured auth key (for example, an attacker-controlled `cr.io` matches a configured `ghcr.io`).

**Who is impacted:** Any consumer of `@sigstore/oci` that uploads artifacts to an OCI registry using credentials from a Docker config, where the destination registry/image reference can be influenced by an untrusted party. This includes `@actions/attest` and the `actions/attest`, `actions/attest-build-provenance`, and `actions/attest-sbom` GitHub Actions when run with `push-to-registry: true`, where the `subject-name` input determines the destination registry.

This is classified as a **critical** vulnerability given the potential, in a theoretical worst-case scenario, to expose long-lived registry credentials. However, in practice, exploitation requires all of the following:

- The Docker config on the host contains credentials for a registry.
- The destination registry/image reference is influenced by an untrusted source.
- The attacker controls a registry whose hostname is a substring of (or is otherwise contained within) a configured Docker auth key.

Under those conditions, registry credentials present on the host (e.g. a GHCR, Docker Hub, or cloud-registry token) can be sent to an attacker-controlled registry during the authentication exchange.

### Patches

Fixed in **`@sigstore/oci@0.7.1`**. Credential selection now requires an **exact host match**: both the target registry and each Docker auth key are canonicalized — stripping any `https?://` scheme and path and normalizing the Docker Hub aliases (`index.docker.io` / `registry-1.docker.io` / `docker.io`) — and compared for equality. When no exact match exists, credential lookup now fails rather than falling back to an unrelated credential.

- **Affected versions:** `<= 0.7.0` (all releases from `0.1.0`).
- **Patched version:** `0.7.1`.

Downstream consumers should pick up the patched `@sigstore/oci`; subsequent releases of `@actions/attest` and the `actions/attest*` GitHub Actions will bundle the fix.

### Workarounds

- Treat the destination registry/image reference as trusted input — do not allow untrusted sources to influence the registry/image reference passed to `@sigstore/oci` (or the `subject-name` of `actions/attest*` when `push-to-registry: true`).
- Limit the credentials available in the host's Docker config to only those required for the operation, and avoid authenticating to registries whose hostnames have substring relationships with potential untrusted destinations.
- Scope registry tokens narrowly and prefer short-lived credentials.

## Affected packages

- `@sigstore/oci < 0.7.1`

## Remediation

Upgrade to a patched release:

- `@sigstore/oci 0.7.1`