GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-45283 (GCVE-0-2026-45283)

Vulnerability from cvelistv5 – Published: 2026-06-01 16:53 – Updated: 2026-06-01 21:42
VLAI
Title
Nextcloud: Files Lock app allows users to lock and unlock files of other users
Summary
Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in error responses, allowing attackers to remove token-based locks placed by other users' client applications. It is recommended that the Nextcloud Server is upgraded to 32.0.2 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 31.0.14.4 or 32.0.2 or 33.0.1
Severity
6.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-01 21:41 UTC
CWE
  • CWE-287 - Improper Authentication
Assigner
References
Impacted products
Vendor Product Version CPE status
nextcloud security-advisories Affected: >= 32.0.0, < 32.0.2
Affected: >= 33.0.0, < 33.0.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-45283",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-01T21:41:51.211198Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-01T21:42:51.254Z",
          "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 32.0.2"
            },
            {
              "status": "affected",
              "version": "\u003e= 33.0.0, \u003c 33.0.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in error responses, allowing attackers to remove token-based locks placed by other users\u0027 client applications. It is recommended that the Nextcloud Server is upgraded to 32.0.2 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 31.0.14.4 or 32.0.2 or 33.0.1"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 6.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-287",
              "description": "CWE-287: Improper Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-01T16:53:50.656Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4chh-6mhf-p4jj",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4chh-6mhf-p4jj"
        },
        {
          "name": "https://github.com/nextcloud/files_lock/pull/1007",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nextcloud/files_lock/pull/1007"
        },
        {
          "name": "https://hackerone.com/reports/3301553#",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://hackerone.com/reports/3301553#"
        }
      ],
      "source": {
        "advisory": "GHSA-4chh-6mhf-p4jj",
        "discovery": "UNKNOWN"
      },
      "title": "Nextcloud: Files Lock app allows users to lock and unlock files of other users"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45283",
    "datePublished": "2026-06-01T16:53:50.656Z",
    "dateReserved": "2026-05-11T18:41:13.158Z",
    "dateUpdated": "2026-06-01T21:42:51.254Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-45283",
      "date": "2026-09-15",
      "epss": "0.00211",
      "percentile": "0.11515"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-45283\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-06-01T19:16:50.523\",\"lastModified\":\"2026-07-22T07:10:00.107\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in error responses, allowing attackers to remove token-based locks placed by other users\u0027 client applications. It is recommended that the Nextcloud Server is upgraded to 32.0.2 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 31.0.14.4 or 32.0.2 or 33.0.1\"},{\"lang\":\"es\",\"value\":\"Nextcloud es una plataforma de colaboraci\u00f3n de contenido de c\u00f3digo abierto. En el Servidor Nextcloud desde las versiones 32.0.0 hasta antes de la 32.0.2, y de la 33.0.0 hasta antes de la 33.0.1, la aplicaci\u00f3n files_lock no validaba correctamente la propiedad de los archivos al procesar solicitudes de bloqueo y desbloqueo DAV. Un usuario autenticado pod\u00eda bloquear o desbloquear archivos pertenecientes a otros usuarios al apuntar a sus rutas WebDAV absolutas. Adem\u00e1s, los tokens de bloqueo se revelaban a llamadores no autorizados en las respuestas de error, permitiendo a los atacantes eliminar bloqueos basados en tokens colocados por las aplicaciones cliente de otros usuarios. Se recomienda que el Servidor Nextcloud se actualice a la 32.0.2 o a la 33.0.1. Se recomienda que el Servidor Nextcloud Enterprise se actualice a la 31.0.14.4 o a la 32.0.2 o a la 33.0.1\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"nextcloud\",\"product\":\"security-advisories\",\"versions\":[{\"version\":\"\u003e= 32.0.0, \u003c 32.0.2\",\"status\":\"affected\"},{\"version\":\"\u003e= 33.0.0, \u003c 33.0.1\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L\",\"baseScore\":6.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":2.8,\"impactScore\":3.4},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N\",\"baseScore\":4.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.8,\"impactScore\":1.4}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-06-01T21:41:51.211198Z\",\"id\":\"CVE-2026-45283\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-287\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*\",\"versionStartIncluding\":\"32.0.0\",\"versionEndExcluding\":\"32.0.2\",\"matchCriteriaId\":\"C7889518-FEB7-4E1A-ABB5-2963751ECE2E\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*\",\"versionStartIncluding\":\"33.0.0\",\"versionEndExcluding\":\"33.0.1\",\"matchCriteriaId\":\"D6F7DDBC-EB8E-4896-AAFA-5E9429D33171\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*\",\"versionStartIncluding\":\"31.0.0\",\"versionEndExcluding\":\"31.0.14.4\",\"matchCriteriaId\":\"BC3E4813-768E-43A4-80C7-F846792A608C\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*\",\"versionStartIncluding\":\"32.0.0\",\"versionEndExcluding\":\"32.0.2\",\"matchCriteriaId\":\"822422E4-FA65-4067-B365-0A1CA032D092\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*\",\"versionStartIncluding\":\"33.0.0\",\"versionEndExcluding\":\"33.0.1\",\"matchCriteriaId\":\"796A254B-835F-41AB-9494-EFFD4DA039CD\"}]}]}],\"references\":[{\"url\":\"https://github.com/nextcloud/files_lock/pull/1007\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Issue Tracking\",\"Patch\"]},{\"url\":\"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4chh-6mhf-p4jj\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Vendor Advisory\"]},{\"url\":\"https://hackerone.com/reports/3301553#\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Permissions Required\"]}]}}",
    "redhat_vex": {
      "current_release_date": "2026-06-28T11:04:40+00:00",
      "cve": "CVE-2026-45283",
      "id": "CVE-2026-45283",
      "initial_release_date": "2026-06-01T16:53:50.656000+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "nextcloud-server: Nextcloud Server: Unauthorized file modification and denial of service via improper WebDAV handling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45283.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-06-04T02:23:08Z",
      "cve": "CVE-2026-45283",
      "id": "CVE-2026-45283",
      "initial_release_date": "2026-06-04T02:23:08Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-45283",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-45283.json",
      "version": "2"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-45283\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-06-01T21:41:51.211198Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-06-01T21:41:54.940Z\"}}], \"cna\": {\"title\": \"Nextcloud: Files Lock app allows users to lock and unlock files of other users\", \"source\": {\"advisory\": \"GHSA-4chh-6mhf-p4jj\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 6.3, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"LOW\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"vendor\": \"nextcloud\", \"product\": \"security-advisories\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003e= 32.0.0, \u003c 32.0.2\"}, {\"status\": \"affected\", \"version\": \"\u003e= 33.0.0, \u003c 33.0.1\"}]}], \"references\": [{\"url\": \"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4chh-6mhf-p4jj\", \"name\": \"https://github.com/nextcloud/security-advisories/security/advisories/GHSA-4chh-6mhf-p4jj\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/nextcloud/files_lock/pull/1007\", \"name\": \"https://github.com/nextcloud/files_lock/pull/1007\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://hackerone.com/reports/3301553#\", \"name\": \"https://hackerone.com/reports/3301553#\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in error responses, allowing attackers to remove token-based locks placed by other users\u0027 client applications. It is recommended that the Nextcloud Server is upgraded to 32.0.2 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 31.0.14.4 or 32.0.2 or 33.0.1\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-287\", \"description\": \"CWE-287: Improper Authentication\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-06-01T16:53:50.656Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-45283\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-06-01T21:42:51.254Z\", \"dateReserved\": \"2026-05-11T18:41:13.158Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-06-01T16:53:50.656Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • 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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.