Matrix Javascript SDK vulnerable to Olm/Megolm protocol confusion

{
  "id": "23ad8dedea00b51f6834c38f7a58d40e6651d9c6749e04b79dead305a684871d",
  "url": "https://osv.dev/vulnerability/CVE-2022-39251",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Matrix Javascript SDK vulnerable to Olm/Megolm protocol confusion",
    "summary": "Matrix Javascript SDK is the Matrix Client-Server SDK for JavaScript. Prior to version 19.7.0, an attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. Starting with version 19.7.0, matrix-js-sdk has been modified to only accept Olm-encrypted to-device messages. Out of caution, several other checks have been audited or added. This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround.",
    "evidence": "osv:CVE-2022-39251",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2022-39251",
      "aliases": [
        "CVE-2022-39251",
        "GHSA-r48r-j8fx-mq2c"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/matrix-org/matrix-js-sdk",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2d067ad95778b26aed24b801be0951e215c3ac8c"
                },
                {
                  "fixed": "a587d7c36026fe1fcf93dfff63588abee359be76"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:matrix:javascript_sdk:*:*:*:*:*:node.js:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "19.7.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "a587d7c36026fe1fcf93dfff63588abee359be76"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "2d067ad95778b26aed24b801be0951e215c3ac8c"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v19.7.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v19.6.0",
            "v19.6.0-rc.1",
            "v8.1.0",
            "v8.1.0-rc.1",
            "v8.0.0",
            "v7.1.0",
            "v7.1.0-rc.1",
            "v5.0.1",
            "v2.4.1",
            "v2.0.1",
            "v2.0.1-rc.2",
            "v2.0.1-rc.1",
            "v1.0.0",
            "v1.0.0-rc.2",
            "v1.0.0-rc.1",
            "v0.11.0",
            "v0.11.0-rc.1",
            "v0.10.7",
            "v0.10.7-rc.1",
            "v0.10.5",
            "v0.10.5-rc.1",
            "v0.10.3",
            "v0.10.2",
            "v0.10.3-rc.1",
            "v0.10.2-rc.1",
            "v0.8.3",
            "v0.8.3-rc.1",
            "v0.8.2",
            "v0.8.1",
            "v0.8.1-rc.1",
            "v0.8.0",
            "v0.7.10",
            "v0.7.9",
            "v0.7.4",
            "v0.7.4-rc.1",
            "v0.7.2",
            "v0.7.1-rc.1",
            "v0.6.4",
            "v0.6.4-rc.2",
            "v0.6.2",
            "v0.6.1",
            "v0.6.0-rc2",
            "v0.6.0-rc1",
            "v0.5.6",
            "v0.5.5",
            "v0.5.4",
            "v0.5.3",
            "v0.5.2",
            "v0.5.1",
            "v0.5.0",
            "v0.4.2",
            "v0.4.1",
            "v0.2.2",
            "v0.2.1",
            "v0.2.0",
            "v0.1.1",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-39251.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.148670373Z",
      "provider": "osv",
      "references": [
        "https://github.com/matrix-org/matrix-js-sdk/releases/tag/v19.7.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39251.json",
        "https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-r48r-j8fx-mq2c",
        "https://nvd.nist.gov/vuln/detail/CVE-2022-39251",
        "https://security.gentoo.org/glsa/202210-35",
        "https://github.com/matrix-org/matrix-js-sdk/commit/a587d7c36026fe1fcf93dfff63588abee359be76",
        "https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clients"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-287",
          "CWE-322"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39251.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2022-39251",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509841,
  "published_at": "2022-09-28T00:00:00+00:00"
}