{"id":"CVE-2026-59891","aliases":["GHSA-pf56-329r-95rw"],"url":"https://o3.security/vulnerability/CVE-2026-59891","summary":"Credential confusion in  @sigstore/oci  can leak registry credentials to an attacker-controlled registry","details":"### Impact\n\nThis is a credential-exposure / credential-confusion issue.\n\n`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:\n\n```js\nObject.keys(dockerConfig.auths || {}).find((key) => key.includes(registry))\n```\n\nBecause 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`).\n\n**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.\n\nThis 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:\n\n- The Docker config on the host contains credentials for a registry.\n- The destination registry/image reference is influenced by an untrusted source.\n- The attacker controls a registry whose hostname is a substring of (or is otherwise contained within) a configured Docker auth key.\n\nUnder 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.\n\n### Patches\n\nFixed 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.\n\n- **Affected versions:** `<= 0.7.0` (all releases from `0.1.0`).\n- **Patched version:** `0.7.1`.\n\nDownstream consumers should pick up the patched `@sigstore/oci`; subsequent releases of `@actions/attest` and the `actions/attest*` GitHub Actions will bundle the fix.\n\n### Workarounds\n\n- 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`).\n- 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.\n- Scope registry tokens narrowly and prefer short-lived credentials.","published":"2026-07-14T16:54:50.608Z","modified":"2026-09-08T03:30:29.367464067Z","cvss":{"score":9.6,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H"},"epss":{"score":0.00473,"percentile":0.39928,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@sigstore/oci","fixedVersion":"0.7.1"}],"fix":{"url":"https://github.com/sigstore/sigstore-js/commit/85c58380758b97ce1b74ef470e55cc21f9d3aa89","label":"sigstore/sigstore-js@85c5838"},"references":[{"type":"WEB","url":"https://github.com/sigstore/sigstore-js/releases/tag/%40sigstore%2Foci%400.7.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59891.json"},{"type":"ADVISORY","url":"https://github.com/sigstore/sigstore-js/security/advisories/GHSA-pf56-329r-95rw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59891"},{"type":"FIX","url":"https://github.com/sigstore/sigstore-js/commit/85c58380758b97ce1b74ef470e55cc21f9d3aa89"},{"type":"PACKAGE","url":"https://github.com/sigstore/sigstore-js"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-08T03:30:29.367464067Z"}}