{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "mbedtls"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6.4-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "mbedtls"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6.4-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In MbedTLS 3.3.0 before 3.6.4, mbedtls_lms_verify may accept invalid signatures if hash computation fails and internal errors go unchecked, enabling LMS (Leighton-Micali Signature) forgery in a fault scenario. Specifically, unchecked return values in mbedtls_lms_verify allow an attacker (who can induce a hardware hash accelerator fault) to bypass LMS signature verification by reusing stale stack data, resulting in acceptance of an invalid signature. In mbedtls_lms_verify, the return values of the internal Merkle tree functions create_merkle_leaf_value and create_merkle_internal_value are not checked. These functions return an integer that indicates whether the call succeeded or not. If a failure occurs, the output buffer (Tc_candidate_root_node) may remain uninitialized, and the result of the signature verification is unpredictable. When the software implementation of SHA-256 is used, these functions will not fail. However, with hardware-accelerated hashing, an attacker could use fault injection against the accelerator to bypass verification.",
  "id": "DEBIAN-CVE-2025-49600",
  "modified": "2026-04-28T19:51:17.407132345Z",
  "published": "2025-07-04T15:15:22.277Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2025-49600"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2025-49600"
  ]
}