{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.12.0"
              },
              {
                "fixed": "0.16.1"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "b41efb063e1faa6579a22dd822777d9e2ce5af81"
            },
            {
              "fixed": "ed148665d211ae97d4672437561ddeccf8556f0d"
            }
          ],
          "repo": "https://github.com/matrix-org/matrix-rust-sdk",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-wfq4-36m3-9g42"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-290"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45056.json"
  },
  "details": "matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue.",
  "id": "CVE-2026-45056",
  "modified": "2026-09-15T03:30:29.899146113Z",
  "published": "2026-09-11T21:13:56.332Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45056.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45056"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0159.html"
    },
    {
      "type": "FIX",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/pull/6553"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution"
}