{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:distribution_project:distribution:*:*:*:*:*:go:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.1.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "708f8d6b060248fe7192294dd5440320ffc86da0"
            }
          ],
          "repo": "https://github.com/distribution/distribution",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-3p65-76g6-3w7r"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33540.json"
  },
  "details": "Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, in pull-through cache mode, distribution discovers token auth endpoints by parsing WWW-Authenticate challenges returned by the configured upstream registry. The realm URL from a bearer challenge is used without validating that it matches the upstream registry host. As a result, an attacker-controlled upstream (or an attacker with MitM position to the upstream) can cause distribution to send the configured upstream credentials via basic auth to an attacker-controlled realm URL. This vulnerability is fixed in 3.1.0.",
  "id": "CVE-2026-33540",
  "modified": "2026-07-08T05:38:31.346962149Z",
  "published": "2026-04-06T14:55:04.812Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33540.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/distribution/distribution/security/advisories/GHSA-3p65-76g6-3w7r"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33540"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Distribution affected by pull-through cache credential exfiltration via www-authenticate bearer realm"
}