{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "8.11.0"
              },
              {
                "fixed": "8.21.0"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "b1ef0e1a01c0bb6ee5367bd9c186a603bde3615a"
            },
            {
              "fixed": "68720b4837284335b2d63cb358f8f6ce65f5bc55"
            }
          ],
          "repo": "https://github.com/curl/curl",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "curl",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9545.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "8.20.0"
          },
          {
            "last_affected": "8.20.0"
          },
          {
            "introduced": "8.19.0"
          },
          {
            "last_affected": "8.19.0"
          },
          {
            "introduced": "8.18.0"
          },
          {
            "last_affected": "8.18.0"
          },
          {
            "introduced": "8.17.0"
          },
          {
            "last_affected": "8.17.0"
          },
          {
            "introduced": "8.16.0"
          },
          {
            "last_affected": "8.16.0"
          },
          {
            "introduced": "8.15.0"
          },
          {
            "last_affected": "8.15.0"
          },
          {
            "introduced": "8.14.1"
          },
          {
            "last_affected": "8.14.1"
          },
          {
            "introduced": "8.14.0"
          },
          {
            "last_affected": "8.14.0"
          },
          {
            "introduced": "8.13.0"
          },
          {
            "last_affected": "8.13.0"
          },
          {
            "introduced": "8.12.1"
          },
          {
            "last_affected": "8.12.1"
          },
          {
            "introduced": "8.12.0"
          },
          {
            "last_affected": "8.12.0"
          },
          {
            "introduced": "8.11.1"
          },
          {
            "last_affected": "8.11.1"
          },
          {
            "introduced": "8.11.0"
          },
          {
            "last_affected": "8.11.0"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "In this scenario, libcurl first uses a proper HTTP/3 server for the initial\ntransfers, and when it makes a second transfer to the same site it has been\nreplaced by the attacker's impostor machine - without a valid certificate.\n\nWhen libcurl returns to the hostname the second time with a cached SSL session\n(`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the\n`CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might\nsend off the second request's bytes on that new connection *before* enforcing\nthe certificate verification failure. Potentially leaking sensitive\ninformation.",
  "id": "CVE-2026-9545",
  "modified": "2026-07-15T01:49:14.531500938Z",
  "published": "2026-07-03T06:17:55.931Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://curl.se/docs/CVE-2026-9545.html"
    },
    {
      "type": "WEB",
      "url": "https://curl.se/docs/CVE-2026-9545.json"
    },
    {
      "type": "WEB",
      "url": "https://hackerone.com/reports/3752888"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9545.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9545"
    }
  ],
  "schema_version": "1.8.0",
  "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": "exposing HTTP/3 early data"
}