punchin-email: Operator inbox (FORWARD_TO) disclosed to correspondents on reply — Cloudflare forward() drops the relay Reply-To

{
  "id": "34edc607b9ddfb5b3a28c765dff786662afef88a80b9ff8f35c73aa36fdca662",
  "url": "https://osv.dev/vulnerability/CVE-2026-54649",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "punchin-email: Operator inbox (FORWARD_TO) disclosed to correspondents on reply — Cloudflare forward() drops the relay Reply-To",
    "summary": "punchin-email is a Cloudflare Email Worker that provides two-way role aliases while relaying mail to a private inbox. Prior to 1.5.0, handleInbound delivers inbound alias mail with message.forward(), which silently drops the added Reply-To header intended to route responses through the relay. When a correspondent sends mail to an alias and the operator replies, the mail client can send directly to the correspondent from the private FORWARD_TO inbox address, exposing that address. The disclosure is limited to the operator's own email address and does not expose third-party data or provide code execution or authentication bypass. This issue is fixed in version 1.5.0.",
    "evidence": "osv:CVE-2026-54649",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-54649",
      "aliases": [
        "CVE-2026-54649",
        "GHSA-2ph7-69xm-hmwv"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/punchin-app/punchin-email",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "593685ffc0b8eb3949a4838e7bfe1e97b953d084"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.5.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "593685ffc0b8eb3949a4838e7bfe1e97b953d084"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "593685ffc0b8eb3949a4838e7bfe1e97b953d084"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.5.0"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.5.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.4.0",
            "v1.3.1",
            "v1.3.0",
            "v1.2.6",
            "v1.2.5",
            "v1.2.4",
            "v1.2.3",
            "v1.2.2",
            "v1.2.1",
            "v1.2.0",
            "v1.1.1",
            "v1.1.0",
            "v1.0.1",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54649.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.801664690Z",
      "provider": "osv",
      "references": [
        "https://github.com/PunchIn-App/punchin-email/releases/tag/v1.5.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54649.json",
        "https://github.com/PunchIn-App/punchin-email/security/advisories/GHSA-2ph7-69xm-hmwv",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-54649",
        "https://github.com/PunchIn-App/punchin-email/commit/593685ffc0b8eb3949a4838e7bfe1e97b953d084",
        "https://github.com/PunchIn-App/punchin-email/pull/66"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-200",
          "CWE-201"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54649.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-54649",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 518435,
  "published_at": "2026-09-17T18:29:23.937+00:00"
}