{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.20.0"
      },
      "package": {
        "ecosystem": "Go",
        "name": "github.com/edgelesssys/contrast"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.21.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-1289"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-01T18:43:55Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "# Summary\n\n`Config.registryFor` selected a per-registry credential / CA / mirror block by checking `strings.HasSuffix(name, fqdn)` after stripping a single trailing dot.\u00a0\nThe match has no boundary between the configured FQDN and any preceding characters in the request hostname.\nA registry configured as `[registries.\"ghcr.io.\"]` is therefore also applied to any image pulled from a host whose name happens to end in the literal byte sequence `ghcr.io`,\u00a0\nincluding attacker-registered domains such as `evilghcr.io.`\u00a0\nThe imagepuller would then send the configured `Authorization` header (basic auth, registry token, or identity token), trust the configured custom CA bundle,\nfollow the configured mirror, or honour `insecure-skip-verify`, on requests to that hostname.\n\n# Prerequisites\n\nFor this to be applicable, an image or layer must be pulled from a \"sibling\" domain ending in one of the FQDNs configured in the imagepuller config.\nThis may occur due to malicious intent or coincidentally.\n\n# Impact\n\n- Authentication header leaks to the sibling registry.\n- If `insecure-skip-verify` is set on an FQDN, TLS will also not be verified for the sibling registry.\n- Mirrors configured for an FQDN will also be used with the sibling registry.\n\n## Not impacted\n\nImage integrity is **not** impacted. Image bytes remain pinned by digest in the policy and are validated after the pull.\nThis advisory does not allow code substitution.\n\n# Workaround\n\n- If possible, configure explicit subdomains in the imagepuller config. A configuration for `[registries.\".example.registry\"]` is unaffected, only `[registries.\"example.registry\"]` is potentially affected.\n- Audit images and layers configured in the deployment for the existence of sibling domains.\n\n# Patches\n\nAfter this patch, registry matches are determined by exact label equality instead of suffix matching.\nEach `.`-separated part of the FQDN must be an exact match with the corresponding label in the image reference.\n\n# Severity\n\n- `AV:N` because the leak is over the network to a registry under the attacker\u0027s control.\u00a0\n- `AC:H` because exploitation requires the operator to have configured a registry FQDN without a leading `.` AND the attacker to control a sibling-suffix domain that the deployment will pull from.\n- `PR:N` for the eventual recipient.\u00a0\n- `S:U` because impact stays in the imagepuller.\u00a0\n- `C:L` for credential leak (no integrity / availability impact).",
  "id": "GHSA-6c87-g9pw-78fx",
  "modified": "2026-07-01T18:43:56Z",
  "published": "2026-07-01T18:43:55Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/edgelesssys/contrast/security/advisories/GHSA-6c87-g9pw-78fx"
    },
    {
      "type": "WEB",
      "url": "https://github.com/edgelesssys/contrast/commit/10826b1d82613025767fb094e8aa51a7dcfbd2a1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/edgelesssys/contrast"
    },
    {
      "type": "WEB",
      "url": "https://github.com/edgelesssys/contrast/releases/tag/v1.21.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Contrast\u0027s Imagepuller registryFor uses unanchored suffix matching, leaking auth credentials and trusted CA configuration to sibling-domain registries"
}