CVE-2026-45691 (GCVE-0-2026-45691)
Vulnerability from cvelistv5
Published
2026-06-01 17:09
Modified
2026-06-01 19:10
Severity ?
5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N
CWE
  • CWE-287 - Improper Authentication
Summary
Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, a pre-2FA session cookie (created after successful password authentication but before TOTP completion) could be reused as a Bearer token to authenticate against DAV endpoints, granting read/write access and bypassing mandatory two-factor authentication. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9 or 29.0.16.16
References
Impacted products
Vendor Product Version
nextcloud security-advisories Version: >= 32.0.0, < 32.0.9
Version: >= 33.0.0, < 33.0.3
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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-45691",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-01T19:09:58.256884Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-01T19:10:18.647Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "security-advisories",
          "vendor": "nextcloud",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 32.0.0, \u003c 32.0.9"
            },
            {
              "status": "affected",
              "version": "\u003e= 33.0.0, \u003c 33.0.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, a pre-2FA session cookie (created after successful password authentication but before TOTP completion) could be reused as a Bearer token to authenticate against DAV endpoints, granting read/write access and bypassing mandatory two-factor authentication. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9 or 29.0.16.16"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N",
            "version": "3.1"
          }
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      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-287",
              "description": "CWE-287: Improper Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-01T17:09:48.217Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-mp6x-g55j-w9jw",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-mp6x-g55j-w9jw"
        },
        {
          "name": "https://github.com/nextcloud/server/pull/59758",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nextcloud/server/pull/59758"
        },
        {
          "name": "https://hackerone.com/reports/3573399",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://hackerone.com/reports/3573399"
        }
      ],
      "source": {
        "advisory": "GHSA-mp6x-g55j-w9jw",
        "discovery": "UNKNOWN"
      },
      "title": "Nextcloud: Bypass of second factor authentication on DAV endpoints"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45691",
    "datePublished": "2026-06-01T17:09:48.217Z",
    "dateReserved": "2026-05-13T04:38:01.164Z",
    "dateUpdated": "2026-06-01T19:10:18.647Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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