{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:trustedfirmware:mbed_tls:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "3.5.0"
              },
              {
                "fixed": "3.6.6"
              },
              {
                "introduced": "4.0.0"
              },
              {
                "fixed": "4.1.0"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "1ec69067fa1351427f904362c1221b31538c8b57"
            },
            {
              "fixed": "0bebf8b8c7f07abe3571ded48a11aa907a1ffb20"
            },
            {
              "introduced": "ec4044008d2d069da38288bc76b0fee34ec78646"
            },
            {
              "fixed": "0fe989b6b514192783c469039edd325fd0989806"
            }
          ],
          "repo": "https://github.com/mbed-tls/mbedtls",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "mitre",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34873.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "3.5.0"
          },
          {
            "fixed": "4.0.0"
          }
        ],
        "source": "DESCRIPTION"
      }
    ]
  },
  "details": "An issue was discovered in Mbed TLS 3.5.0 through 4.0.0. Client impersonation can occur while resuming a TLS 1.3 session.",
  "id": "CVE-2026-34873",
  "modified": "2026-07-15T01:48:54.015858909Z",
  "published": "2026-04-01T00:00:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34873.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://mbed-tls.readthedocs.io/en/latest/security-advisories/"
    },
    {
      "type": "ADVISORY",
      "url": "https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-client-impersonation-while-resuming-tls13-session/"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34873"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}