critical

CVE-2026-59891

npm · @sigstore/oci

Summary

Credential confusion in @sigstore/oci can leak registry credentials to an attacker-controlled registry

Severity
critical
CVSS
9.6
EPSS
0.5% (p41)
CWE
CWE-522
Also known as
GHSA-pf56-329r-95rw
Published
2026-07-21
Updated
2026-07-21

Advisory details

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:

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:

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.

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

References

Related advisories

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Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.