CVE-2026-6555 (GCVE-0-2026-6555)

Vulnerability from cvelistv5 – Published: 2026-05-20 01:25 – Updated: 2026-05-20 13:15
VLAI
Title
ProSolution WP Client <= 2.0.0 - Unauthenticated Arbitrary File Upload via 'files'
Summary
The ProSolution WP Client plugin for WordPress is vulnerable to Arbitrary File Upload in versions up to, and including, 2.0.0. This is due to an array validation mismatch where only the first file in the upload array undergoes extension and MIME type validation, while all files are processed and uploaded to a web-accessible directory. This makes it possible for unauthenticated attackers to upload malicious PHP files and achieve remote code execution by sending a valid first file followed by a malicious file.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
  • CWE-434 - Unrestricted Upload of File with Dangerous Type
Assigner
References
Impacted products
Vendor Product Version
prosolution ProSolution WP Client Affected: 0 , ≤ 2.0.0 (semver)
Create a notification for this product.
Credits
Achmad Zaenuri Dahlan Putra
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-6555",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-20T13:15:31.571596Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-20T13:15:40.373Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "ProSolution WP Client",
          "vendor": "prosolution",
          "versions": [
            {
              "lessThanOrEqual": "2.0.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Achmad Zaenuri Dahlan Putra"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The ProSolution WP Client plugin for WordPress is vulnerable to Arbitrary File Upload in versions up to, and including, 2.0.0. This is due to an array validation mismatch where only the first file in the upload array undergoes extension and MIME type validation, while all files are processed and uploaded to a web-accessible directory. This makes it possible for unauthenticated attackers to upload malicious PHP files and achieve remote code execution by sending a valid first file followed by a malicious file."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-434",
              "description": "CWE-434 Unrestricted Upload of File with Dangerous Type",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-20T01:25:45.499Z",
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence"
      },
      "references": [
        {
          "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/0b870d35-7e10-4fb5-8c3b-2bf299d1f3d5?source=cve"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/public/class-prosolwpclient-public.php#L1072"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/public/class-prosolwpclient-public.php#L1072"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/includes/UploadHandler.php#L1345"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/includes/UploadHandler.php#L1345"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/includes/UploadHandler.php#L384"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/includes/UploadHandler.php#L384"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/public/class-prosolwpclient-public.php#L998"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/public/class-prosolwpclient-public.php#L998"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-05-19T12:03:25.000Z",
          "value": "Disclosed"
        }
      ],
      "title": "ProSolution WP Client \u003c= 2.0.0 - Unauthenticated Arbitrary File Upload via \u0027files\u0027"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
    "assignerShortName": "Wordfence",
    "cveId": "CVE-2026-6555",
    "datePublished": "2026-05-20T01:25:45.499Z",
    "dateReserved": "2026-04-17T23:02:07.358Z",
    "dateUpdated": "2026-05-20T13:15:40.373Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-6555",
      "date": "2026-06-16",
      "epss": "0.00952",
      "percentile": "0.56584"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-6555\",\"sourceIdentifier\":\"security@wordfence.com\",\"published\":\"2026-05-20T02:16:38.930\",\"lastModified\":\"2026-05-20T13:54:54.890\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The ProSolution WP Client plugin for WordPress is vulnerable to Arbitrary File Upload in versions up to, and including, 2.0.0. This is due to an array validation mismatch where only the first file in the upload array undergoes extension and MIME type validation, while all files are processed and uploaded to a web-accessible directory. This makes it possible for unauthenticated attackers to upload malicious PHP files and achieve remote code execution by sending a valid first file followed by a malicious file.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security@wordfence.com\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"security@wordfence.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-434\"}]}],\"references\":[{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/includes/UploadHandler.php#L1345\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/includes/UploadHandler.php#L384\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/public/class-prosolwpclient-public.php#L1072\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/public/class-prosolwpclient-public.php#L998\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/includes/UploadHandler.php#L1345\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/includes/UploadHandler.php#L384\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/public/class-prosolwpclient-public.php#L1072\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/public/class-prosolwpclient-public.php#L998\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://www.wordfence.com/threat-intel/vulnerabilities/id/0b870d35-7e10-4fb5-8c3b-2bf299d1f3d5?source=cve\",\"source\":\"security@wordfence.com\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-6555\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-20T13:15:31.571596Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-20T13:15:37.290Z\"}}], \"cna\": {\"title\": \"ProSolution WP Client \u003c= 2.0.0 - Unauthenticated Arbitrary File Upload via \u0027files\u0027\", \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Achmad Zaenuri Dahlan Putra\"}], \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 9.8, \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\"}}], \"affected\": [{\"vendor\": \"prosolution\", \"product\": \"ProSolution WP Client\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"2.0.0\"}], \"defaultStatus\": \"unaffected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-05-19T12:03:25.000Z\", \"value\": \"Disclosed\"}], \"references\": [{\"url\": \"https://www.wordfence.com/threat-intel/vulnerabilities/id/0b870d35-7e10-4fb5-8c3b-2bf299d1f3d5?source=cve\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/public/class-prosolwpclient-public.php#L1072\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/public/class-prosolwpclient-public.php#L1072\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/includes/UploadHandler.php#L1345\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/includes/UploadHandler.php#L1345\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/includes/UploadHandler.php#L384\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/includes/UploadHandler.php#L384\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/trunk/public/class-prosolwpclient-public.php#L998\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/prosolution-wp-client/tags/2.0.0/public/class-prosolwpclient-public.php#L998\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"The ProSolution WP Client plugin for WordPress is vulnerable to Arbitrary File Upload in versions up to, and including, 2.0.0. This is due to an array validation mismatch where only the first file in the upload array undergoes extension and MIME type validation, while all files are processed and uploaded to a web-accessible directory. This makes it possible for unauthenticated attackers to upload malicious PHP files and achieve remote code execution by sending a valid first file followed by a malicious file.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-434\", \"description\": \"CWE-434 Unrestricted Upload of File with Dangerous Type\"}]}], \"providerMetadata\": {\"orgId\": \"b15e7b5b-3da4-40ae-a43c-f7aa60e62599\", \"shortName\": \"Wordfence\", \"dateUpdated\": \"2026-05-20T01:25:45.499Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-6555\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-20T13:15:40.373Z\", \"dateReserved\": \"2026-04-17T23:02:07.358Z\", \"assignerOrgId\": \"b15e7b5b-3da4-40ae-a43c-f7aa60e62599\", \"datePublished\": \"2026-05-20T01:25:45.499Z\", \"assignerShortName\": \"Wordfence\"}",
      "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.