Vulnerability-Lookup

CVE-2026-55502 (GCVE-0-2026-55502)

Vulnerability from cvelistv5 – Published: 2026-07-31 03:35 – Updated: 2026-07-31 11:09

Title

Cloudreve: OAuth Admin.Read scope can update OneDrive storage policy credentials

Summary

Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, POST /api/v4/admin/policy/oauth/signin requires only Admin.Read even though GetOauthRedirectService persists caller-supplied OneDrive secret and app_id values, allowing an OAuth token without Admin.Write to modify storage policy credentials. The route is inside the admin group that requires Admin.Read, but it does not add the local Admin.Write guard used by sibling policy mutation routes. Its handler persists attacker-supplied secret and app_id values into the selected OneDrive storage policy before returning an OAuth URL. This issue is fixed in version 4.17.0.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-863 - Incorrect Authorization

Assigner

GitHub_M

References

1 reference

URL	Tags
https://github.com/cloudreve/cloudreve/security/a…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
cloudreve	cloudreve	Affected: < 4.17.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55502",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-31T11:08:45.272468Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-31T11:09:00.719Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "cloudreve",
          "vendor": "cloudreve",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 4.17.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, POST /api/v4/admin/policy/oauth/signin requires only Admin.Read even though GetOauthRedirectService persists caller-supplied OneDrive secret and app_id values, allowing an OAuth token without Admin.Write to modify storage policy credentials. The route is inside the admin group that requires Admin.Read, but it does not add the local Admin.Write guard used by sibling policy mutation routes. Its handler persists attacker-supplied secret and app_id values into the selected OneDrive storage policy before returning an OAuth URL. This issue is fixed in version 4.17.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-31T03:35:59.389Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf"
        }
      ],
      "source": {
        "advisory": "GHSA-hq88-5x99-x3gf",
        "discovery": "UNKNOWN"
      },
      "title": "Cloudreve: OAuth Admin.Read scope can update OneDrive storage policy credentials"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55502",
    "datePublished": "2026-07-31T03:35:59.389Z",
    "dateReserved": "2026-06-16T22:28:27.063Z",
    "dateUpdated": "2026-07-31T11:09:00.719Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-55502",
      "date": "2026-08-04",
      "epss": "0.00338",
      "percentile": "0.26436"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-55502\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-31T04:17:23.563\",\"lastModified\":\"2026-07-31T11:17:10.207\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, POST /api/v4/admin/policy/oauth/signin requires only Admin.Read even though GetOauthRedirectService persists caller-supplied OneDrive secret and app_id values, allowing an OAuth token without Admin.Write to modify storage policy credentials. The route is inside the admin group that requires Admin.Read, but it does not add the local Admin.Write guard used by sibling policy mutation routes. Its handler persists attacker-supplied secret and app_id values into the selected OneDrive storage policy before returning an OAuth URL. This issue is fixed in version 4.17.0.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"cloudreve\",\"product\":\"cloudreve\",\"versions\":[{\"version\":\"\u003c 4.17.0\",\"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:N/I:H/A:L\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":2.8,\"impactScore\":4.2}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-31T11:08:45.272468Z\",\"id\":\"CVE-2026-55502\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-863\"}]}],\"references\":[{\"url\":\"https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-55502\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-31T11:08:45.272468Z\"}}}], \"references\": [{\"url\": \"https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-31T11:08:28.686Z\"}}], \"cna\": {\"title\": \"Cloudreve: OAuth Admin.Read scope can update OneDrive storage policy credentials\", \"source\": {\"advisory\": \"GHSA-hq88-5x99-x3gf\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"LOW\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"cloudreve\", \"product\": \"cloudreve\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 4.17.0\"}]}], \"references\": [{\"url\": \"https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf\", \"name\": \"https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf\", \"tags\": [\"x_refsource_CONFIRM\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, POST /api/v4/admin/policy/oauth/signin requires only Admin.Read even though GetOauthRedirectService persists caller-supplied OneDrive secret and app_id values, allowing an OAuth token without Admin.Write to modify storage policy credentials. The route is inside the admin group that requires Admin.Read, but it does not add the local Admin.Write guard used by sibling policy mutation routes. Its handler persists attacker-supplied secret and app_id values into the selected OneDrive storage policy before returning an OAuth URL. This issue is fixed in version 4.17.0.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-863\", \"description\": \"CWE-863: Incorrect Authorization\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-07-31T03:35:59.389Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-55502\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-31T11:09:00.719Z\", \"dateReserved\": \"2026-06-16T22:28:27.063Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-07-31T03:35:59.389Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

GHSA-HQ88-5X99-X3GF

Vulnerability from github – Published: 2026-07-24 20:49 – Updated: 2026-07-24 20:49

Summary

Cloudreve OAuth Admin.Read scope can update OneDrive storage policy credentials

Details

Summary

Cloudreve 4.16.1 has an OAuth scope authorization bypass in the admin storage policy routes. An OAuth bearer token scoped to Admin.Read but not Admin.Write can call POST /api/v4/admin/policy/oauth/signin and update OneDrive storage policy credentials.

The route is inside the admin group that requires Admin.Read, but it does not add the local Admin.Write guard used by sibling policy mutation routes. Its handler persists attacker-supplied secret and app_id values into the selected OneDrive storage policy before returning an OAuth URL.

Impact

An OAuth application that was granted only read-only admin scope can modify persistent storage backend configuration for a OneDrive policy. This can break the storage backend, replace the stored application secret and app ID, and redirect future OAuth setup for that policy to attacker-controlled application parameters. The attack crosses the intended OAuth scope boundary because Admin.Write is required for sibling storage policy mutation routes.

Reproduction

Preconditions:

The instance has a OneDrive storage policy.
An admin user authorizes an OAuth client for Admin.Read but not Admin.Write.
The OAuth client obtains a bearer access token for that admin user.

Send the following request with that read-only admin scoped token:

POST /api/v4/admin/policy/oauth/signin HTTP/1.1
Authorization: Bearer <admin OAuth token scoped to Admin.Read only>
Content-Type: application/json

{"id":1,"secret":"attacker-secret","app_id":"attacker-app-id"}

Expected secure result: the request is rejected with an insufficient-scope error because it changes storage policy credentials.

Actual result: the request reaches AdminOdOAuthURL, and GetOauthRedirectService.GetOAuth() persists the supplied values to the storage policy.

Root cause

routers/router.go applies RequiredScopes(types.ScopeAdminRead) to the authenticated admin route group. Sibling policy mutation routes add local RequiredScopes(types.ScopeAdminWrite) guards, for example policy create, policy update, CORS creation, OAuth callback, and policy delete.

The OneDrive OAuth signin route is missing that local write-scope guard:

oauth.POST("signin",
    controllers.FromJSON[adminsvc.GetOauthRedirectService](adminsvc.GetOauthRedirectParamCtx{}),
    controllers.AdminOdOAuthURL,
)

The handler performs a persistent write in service/admin/policy.go:

policy.Settings.OauthRedirect = routes.MasterPolicyOAuthCallback(dep.SettingProvider().SiteURL(c)).String()
policy.SecretKey = service.Secret
policy.BucketName = service.AppID
policy, err = storagePolicyClient.Upsert(c, policy)

The request fields secret and app_id come directly from the caller.

PoC evidence

A focused scope test confirmed that a request context with only Admin.Read fails CheckScope(c, types.ScopeAdminWrite), while Admin.Write implies Admin.Read. Therefore write routes must add RequiredScopes(types.ScopeAdminWrite) explicitly. The vulnerable route does not do so, and the handler writes the policy fields shown above.

Remediation

Add middleware.RequiredScopes(types.ScopeAdminWrite) to oauth.POST("signin", ...) before the JSON handler. Consider auditing other admin test routes that perform outbound network or mail actions under only Admin.Read, but this persistent credential update should be fixed first.

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 4.0.0-20260613030954-9e9fb43e7288"
      },
      "package": {
        "ecosystem": "Go",
        "name": "github.com/cloudreve/Cloudreve/v4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.17.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/cloudreve/Cloudreve/v3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "3.0.0-20250225100611-da4e44b77af4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55502"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T20:49:14Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\n\nCloudreve 4.16.1 has an OAuth scope authorization bypass in the admin storage policy routes. An OAuth bearer token scoped to `Admin.Read` but not `Admin.Write` can call `POST /api/v4/admin/policy/oauth/signin` and update OneDrive storage policy credentials.\n\nThe route is inside the admin group that requires `Admin.Read`, but it does not add the local `Admin.Write` guard used by sibling policy mutation routes. Its handler persists attacker-supplied `secret` and `app_id` values into the selected OneDrive storage policy before returning an OAuth URL.\n\n## Impact\n\nAn OAuth application that was granted only read-only admin scope can modify persistent storage backend configuration for a OneDrive policy. This can break the storage backend, replace the stored application secret and app ID, and redirect future OAuth setup for that policy to attacker-controlled application parameters. The attack crosses the intended OAuth scope boundary because `Admin.Write` is required for sibling storage policy mutation routes.\n\n## Reproduction\n\nPreconditions:\n\n1. The instance has a OneDrive storage policy.\n2. An admin user authorizes an OAuth client for `Admin.Read` but not `Admin.Write`.\n3. The OAuth client obtains a bearer access token for that admin user.\n\nSend the following request with that read-only admin scoped token:\n\n```http\nPOST /api/v4/admin/policy/oauth/signin HTTP/1.1\nAuthorization: Bearer \u003cadmin OAuth token scoped to Admin.Read only\u003e\nContent-Type: application/json\n\n{\"id\":1,\"secret\":\"attacker-secret\",\"app_id\":\"attacker-app-id\"}\n```\n\nExpected secure result: the request is rejected with an insufficient-scope error because it changes storage policy credentials.\n\nActual result: the request reaches `AdminOdOAuthURL`, and `GetOauthRedirectService.GetOAuth()` persists the supplied values to the storage policy.\n\n## Root cause\n\n`routers/router.go` applies `RequiredScopes(types.ScopeAdminRead)` to the authenticated admin route group. Sibling policy mutation routes add local `RequiredScopes(types.ScopeAdminWrite)` guards, for example policy create, policy update, CORS creation, OAuth callback, and policy delete.\n\nThe OneDrive OAuth signin route is missing that local write-scope guard:\n\n```go\noauth.POST(\"signin\",\n    controllers.FromJSON[adminsvc.GetOauthRedirectService](adminsvc.GetOauthRedirectParamCtx{}),\n    controllers.AdminOdOAuthURL,\n)\n```\n\nThe handler performs a persistent write in `service/admin/policy.go`:\n\n```go\npolicy.Settings.OauthRedirect = routes.MasterPolicyOAuthCallback(dep.SettingProvider().SiteURL(c)).String()\npolicy.SecretKey = service.Secret\npolicy.BucketName = service.AppID\npolicy, err = storagePolicyClient.Upsert(c, policy)\n```\n\nThe request fields `secret` and `app_id` come directly from the caller.\n\n## PoC evidence\n\nA focused scope test confirmed that a request context with only `Admin.Read` fails `CheckScope(c, types.ScopeAdminWrite)`, while `Admin.Write` implies `Admin.Read`. Therefore write routes must add `RequiredScopes(types.ScopeAdminWrite)` explicitly. The vulnerable route does not do so, and the handler writes the policy fields shown above.\n\n## Remediation\n\nAdd `middleware.RequiredScopes(types.ScopeAdminWrite)` to `oauth.POST(\"signin\", ...)` before the JSON handler. Consider auditing other admin test routes that perform outbound network or mail actions under only `Admin.Read`, but this persistent credential update should be fixed first.",
  "id": "GHSA-hq88-5x99-x3gf",
  "modified": "2026-07-24T20:49:14Z",
  "published": "2026-07-24T20:49:14Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cloudreve/cloudreve/commit/9e9fb43e7288924cca052e5fdbb70d5365ef1ede"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/cloudreve/cloudreve"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cloudreve/cloudreve/releases/tag/4.17.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Cloudreve OAuth Admin.Read scope can update OneDrive storage policy credentials"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-55502 (GCVE-0-2026-55502)

GHSA-HQ88-5X99-X3GF

Summary

Impact

Reproduction

Root cause

PoC evidence

Remediation

Tags

Sightings

Nomenclature