FKIE_CVE-2025-66546

Vulnerability from fkie_nvd - Published: 2025-12-05 17:16 - Updated: 2025-12-09 16:36
Severity ?
3.3 (Low) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Summary
Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token. This vulnerability is fixed in 4.7.19, 5.5.6, and 6.0.1.
References
security-advisories@github.comhttps://github.com/nextcloud/calendar/commit/f41650c3681fc4a4130eb883f5c0899c011326b3Patch
security-advisories@github.comhttps://github.com/nextcloud/calendar/pull/7537Issue Tracking
security-advisories@github.comhttps://github.com/nextcloud/security-advisories/security/advisories/GHSA-7x2j-2674-fj95Patch, Vendor Advisory
security-advisories@github.comhttps://hackerone.com/reports/3275810Issue Tracking, Vendor Advisory
Impacted products
Vendor Product Version
nextcloud calendar *
nextcloud calendar *
nextcloud calendar 6.0.0
nextcloud calendar 6.0.0
nextcloud calendar 6.0.0
nextcloud calendar 6.0.0
nextcloud calendar 6.0.0
nextcloud calendar 6.0.0
nextcloud calendar 6.0.0
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "84E1FFC4-516D-4680-9F67-E66C1FAE5E0B",
              "versionEndExcluding": "4.7.19",
              "versionStartIncluding": "4.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "3E716F13-981B-49BA-98FF-3B52C9962EA2",
              "versionEndExcluding": "5.5.6",
              "versionStartIncluding": "5.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:6.0.0:-:*:*:*:*:*:*",
              "matchCriteriaId": "5FEEB806-FB4C-42B4-BE4E-297AB95A854F",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:6.0.0:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1A878DF-8A9B-4987-8E2C-6873CA2C8427",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:6.0.0:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "9B9884CA-4E88-4AB3-BA37-FAF9E845F04E",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:6.0.0:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "032400B7-AE78-467F-81CC-83164AC29796",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:6.0.0:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "D1A265F6-884F-44FF-B00F-CB5F7E704E0E",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:6.0.0:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "8249ACE0-0485-4485-B628-D157E57A91C0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:nextcloud:calendar:6.0.0:rc6:*:*:*:*:*:*",
              "matchCriteriaId": "508556C9-5596-42B5-AD76-8156A42FEED7",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token. This vulnerability is fixed in 4.7.19, 5.5.6, and 6.0.1."
    }
  ],
  "id": "CVE-2025-66546",
  "lastModified": "2025-12-09T16:36:01.357",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 3.3,
          "baseSeverity": "LOW",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2025-12-05T17:16:05.163",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/nextcloud/calendar/commit/f41650c3681fc4a4130eb883f5c0899c011326b3"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking"
      ],
      "url": "https://github.com/nextcloud/calendar/pull/7537"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-7x2j-2674-fj95"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking",
        "Vendor Advisory"
      ],
      "url": "https://hackerone.com/reports/3275810"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


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Sightings

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.