CVE-2026-45155 (GCVE-0-2026-45155)

Vulnerability from cvelistv5 – Published: 2026-06-01 16:38 – Updated: 2026-06-01 18:09
VLAI?
Title
Nextcloud: Private circle can be added to another circle via API
Summary
Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.7 and 33.0.0 to before 33.0.1, a missing access check on API level allowed to add unknown circles by their ID directly to other circles. Since circle IDs have 62^15 complexity by default this is still unlikely to be executable at will, but if access to an ID was available via another source, memberships could be tracked like this. It is recommended that the Nextcloud Server is upgraded to 32.0.7 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 29.0.16.14, 30.0.17.8, 31.0.14.3, 32.0.7 or 33.0.1
Severity ?
2.6 (Low)
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N
CWE
  • CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
Impacted products
Vendor Product Version
nextcloud security-advisories Affected: >= 32.0.0, < 32.0.7
Affected: >= 33.0.0, < 33.0.1
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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-45155",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-01T18:09:03.555046Z",
                "version": "2.0.3"
              },
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        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-01T18:09:28.247Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
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          "vendor": "nextcloud",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 32.0.0, \u003c 32.0.7"
            },
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              "version": "\u003e= 33.0.0, \u003c 33.0.1"
            }
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.7 and 33.0.0 to before 33.0.1, a missing access check on API level allowed to add unknown circles by their ID directly to other circles. Since circle IDs have 62^15 complexity by default this is still unlikely to be executable at will, but if access to an ID was available via another source, memberships could be tracked like this. It is recommended that the Nextcloud Server is upgraded to 32.0.7 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 29.0.16.14, 30.0.17.8, 31.0.14.3, 32.0.7 or 33.0.1"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 2.6,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N",
            "version": "3.1"
          }
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      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-639",
              "description": "CWE-639: Authorization Bypass Through User-Controlled Key",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-01T16:38:33.335Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xpgv-grf9-gm7x",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xpgv-grf9-gm7x"
        },
        {
          "name": "https://github.com/nextcloud/circles/pull/2401",
          "tags": [
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          "url": "https://github.com/nextcloud/circles/pull/2401"
        },
        {
          "name": "https://hackerone.com/reports/3511998",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://hackerone.com/reports/3511998"
        }
      ],
      "source": {
        "advisory": "GHSA-xpgv-grf9-gm7x",
        "discovery": "UNKNOWN"
      },
      "title": "Nextcloud: Private circle can be added to another circle via API"
    }
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  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45155",
    "datePublished": "2026-06-01T16:38:33.335Z",
    "dateReserved": "2026-05-08T20:44:38.964Z",
    "dateUpdated": "2026-06-01T18:09:28.247Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • 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.
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  • 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.