Calendar discovery accepted local file and remote network share locations

{
  "id": "744844acc813c572b1373cd08abca9201bdfeb91bd0f1e752013afd886d639c5",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-118177",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Calendar discovery accepted local file and remote network share locations",
    "summary": "When looking for calendars in a directory on a server, during account setup or when adding a new network calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network shares. A malicious server, or a network attacker when the lookup used plain HTTP, could make Thunderbird subscribe to such a location. On Windows this could leak the user's NTLM credentials to an attacker-controlled host on every calendar refresh, and changes to the calendar could be written to the attacker's share or overwrite a local file. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.",
    "evidence": "cve:CVE-2026-118177",
    "products": [
      {
        "name": {
          "value": "Thunderbird",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-118177",
      "aliases": [
        "CVE-2026-118177"
      ],
      "metrics": [],
      "affected": [
        {
          "vendor": "Mozilla",
          "product": "Thunderbird",
          "versions": [
            {
              "status": "unaffected",
              "version": "153.6",
              "versionType": "rpm",
              "lessThanOrEqual": "153.*"
            },
            {
              "status": "unaffected",
              "version": "159",
              "versionType": "rpm",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ],
      "modified": "2026-10-27T18:27:49.964Z",
      "provider": "cve",
      "references": [
        "https://bugzilla.mozilla.org/show_bug.cgi?id=2080924",
        "https://www.mozilla.org/security/advisories/mfsa2026-121/",
        "https://www.mozilla.org/security/advisories/mfsa2026-122/"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
          "shortName": "mozilla",
          "dateUpdated": "2026-10-27T18:27:49.964Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-118177",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-cve",
  "document_id": 398031,
  "published_at": "2026-10-27T18:16:31.083+00:00"
}