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CVE-2025-66554

Status: AnalyzedMedium (5.4)—

Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. Prior to 5.5.4, 6.0.6, and 7.2.5, a malicious user was able to modify their organisation and title field to load additional CSS files. Javascript and other options were correctly blocked by the content security policy of the Nextcloud Server code. This vulnerability is fixed in 5.5.4, 6.0.6, and 7.2.5.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Nextcloud — Contacts

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2025-66554",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-66554",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-12-08T19:50:53.342639Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 3.5,
          "attackVector": "NETWORK",
          "baseSeverity": "LOW",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 2.1
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "CHANGED",
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          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "REQUIRED",
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          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.7,
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      }
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  },
  "affected": [
    {
      "source": "security-advisories@github.com",
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          "product": "security-advisories",
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              "status": "affected",
              "version": ">= 7.0.0-alpha.1, < 7.2.5"
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            {
              "status": "affected",
              "version": ">= 6.0.0-alpha1, < 6.0.6"
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              "status": "affected",
              "version": "< 5.5.4"
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  "published": "2025-12-05T18:15:58.630",
  "references": [
    {
      "url": "https://github.com/nextcloud/contacts/commit/d954d098978dde1f121600e8b994e02f293c68b1",
      "tags": [
        "Patch"
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      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/nextcloud/contacts/pull/4619",
      "tags": [
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        "Patch"
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      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-9v78-cpfc-v6h2",
      "tags": [
        "Patch",
        "Vendor Advisory"
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      "source": "security-advisories@github.com"
    },
    {
      "url": "https://hackerone.com/reports/3293290",
      "tags": [
        "Permissions Required",
        "Vendor Advisory"
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      "source": "security-advisories@github.com"
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  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
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      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. Prior to 5.5.4, 6.0.6, and 7.2.5, a malicious user was able to modify their organisation and title field to load additional CSS files. Javascript and other options were correctly blocked by the content security policy of the Nextcloud Server code. This vulnerability is fixed in 5.5.4, 6.0.6, and 7.2.5."
    }
  ],
  "lastModified": "2026-06-17T09:57:01.223",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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              "versionEndExcluding": "5.5.4",
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            },
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              "matchCriteriaId": "0F4DE317-1CA4-4D75-914D-DF7F1E1A61F1",
              "versionEndExcluding": "6.0.6",
              "versionStartIncluding": "6.0.0"
            },
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              "versionEndExcluding": "7.2.5",
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          "operator": "OR"
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}