/api/v1/jwt/fetch_api_key endpoint can leak if an email address has an account in Zulip server

{
  "id": "f51782a9950ff1fd51f21971100e4e937c74c9334e3d90ed4b300b7d0868b399",
  "url": "https://osv.dev/vulnerability/CVE-2024-56136",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "/api/v1/jwt/fetch_api_key endpoint can leak if an email address has an account in Zulip server",
    "summary": "Zulip server provides an open-source team chat that helps teams stay productive and focused. Zulip Server 7.0 and above are vulnerable to an information disclose attack, where, if a Zulip server is hosting multiple organizations, an unauthenticated user can make a request and determine if an email address is in use by a user. Zulip Server 9.4 resolves the issue, as does the `main` branch of Zulip Server. Users are advised to upgrade. There are no known workarounds for this issue.",
    "evidence": "osv:CVE-2024-56136",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2024-56136",
      "aliases": [
        "CVE-2024-56136",
        "GHSA-5xg8-xhfj-4hm6"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/zulip/zulip",
              "type": "GIT",
              "events": [
                {
                  "introduced": "88873138acde0f6b66dfe09b086e5ab327be940b"
                },
                {
                  "fixed": "b762cdde481456c39a09602f1d7e0e898bdbd876"
                },
                {
                  "fixed": "c6334a765b1e6d71760e4a3b32ae5b8367f2ed4d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:zulip:zulip_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "7.0"
                      },
                      {
                        "fixed": "9.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "c6334a765b1e6d71760e4a3b32ae5b8367f2ed4d"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "9.3",
            "9.2",
            "9.1",
            "9.0",
            "9.0-beta1",
            "8.0",
            "9.0-dev",
            "8.0-beta2",
            "8.0-beta1",
            "8.0-dev",
            "7.0",
            "7.0-beta3",
            "shared-0.0.18",
            "shared-0.0.17",
            "7.0-dev"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-56136.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.293193214Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56136.json",
        "https://github.com/zulip/zulip/security/advisories/GHSA-5xg8-xhfj-4hm6",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-56136",
        "https://github.com/zulip/zulip/commit/c6334a765b1e6d71760e4a3b32ae5b8367f2ed4d"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-200"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56136.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-56136",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493708,
  "published_at": "2025-01-16T19:25:33.261+00:00"
}