CVE-2026-103476 (GCVE-0-2026-103476)

Vulnerability from cvelistv5 – Published: 2026-09-30 17:22 – Updated: 2026-09-30 17:22
VLAI
Title
yii2-starter-kit through 4.2.0 Unauthorized File Download via attachment-download
Summary
yii2-starter-kit through 4.2.0 fails to validate article publication status in the attachment-download endpoint, allowing unauthenticated attackers to download files from draft articles. Attackers can enumerate sequential attachment identifiers to retrieve files from unpublished articles without authentication or authorization checks.
Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CWE
  • CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
Impacted products
Vendor Product Version CPE status
yii2-starter-kit yii2-starter-kit Affected: 0 , ≤ 4.2.0 (custom)
guessed Create a notification for this product.
Date Public
2026-09-30 00:00
Credits
Vikash Gupta
Show details on NVD website
To clipboard 

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          "packageURL": "pkg:composer/yii2-starter-kit/yii2-starter-kit",
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      ],
      "metrics": [
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            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
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            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
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            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE"
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            "confidentialityImpact": "LOW",
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            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
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      "providerMetadata": {
        "dateUpdated": "2026-09-30T17:22:42.463Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Issue #797",
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/yii-starter-kit/yii2-starter-kit/issues/797"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/yii-starter-kit/yii2-starter-kit"
        },
        {
          "tags": [
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          "url": "https://github.com/yii-starter-kit/yii2-starter-kit/blob/cc2c451e8c959c7300b04efea597706a38609f58/frontend/controllers/ArticleController.php#L69"
        },
        {
          "name": "VulnCheck Advisory: yii2-starter-kit through 4.2.0 Unauthorized File Download via attachment-download",
          "tags": [
            "third-party-advisory"
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          "url": "https://www.vulncheck.com/advisories/yii2-starter-kit-through-4.2.0-unauthorized-file-download-via-attachment-download"
        }
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      "title": "yii2-starter-kit through 4.2.0 Unauthorized File Download via attachment-download",
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  "cveMetadata": {
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    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-103476",
    "datePublished": "2026-09-30T17:22:42.463Z",
    "dateReserved": "2026-09-30T16:03:01.107Z",
    "dateUpdated": "2026-09-30T17:22:42.463Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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        "affected": [
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                "product": "yii2-starter-kit",
                "vendor": "yii2-starter-kit",
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        "cveTags": [],
        "descriptions": [
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          }
        ],
        "id": "CVE-2026-103476",
        "lastModified": "2026-09-30T19:08:43.927",
        "metrics": {
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              "cvssData": {
                "attackComplexity": "LOW",
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                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
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                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
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              "impactScore": 1.4,
              "source": "disclosure@vulncheck.com",
              "type": "Primary"
            }
          ],
          "cvssMetricV40": [
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              "cvssData": {
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                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
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                "availabilityRequirement": "NOT_DEFINED",
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                "baseSeverity": "MEDIUM",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "NONE",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "NONE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
                "vulnAvailabilityImpact": "NONE",
                "vulnConfidentialityImpact": "LOW",
                "vulnIntegrityImpact": "NONE",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "disclosure@vulncheck.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-09-30T18:18:17.973",
        "references": [
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            "source": "disclosure@vulncheck.com",
            "url": "https://github.com/yii-starter-kit/yii2-starter-kit"
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            "source": "disclosure@vulncheck.com",
            "url": "https://github.com/yii-starter-kit/yii2-starter-kit/blob/cc2c451e8c959c7300b04efea597706a38609f58/frontend/controllers/ArticleController.php#L69"
          },
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          },
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            "url": "https://www.vulncheck.com/advisories/yii2-starter-kit-through-4.2.0-unauthorized-file-download-via-attachment-download"
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            ],
            "source": "disclosure@vulncheck.com",
            "type": "Primary"
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        ]
      }
    }
  }
}



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Nomenclature

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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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