{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-84695",
        "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "state": "PUBLISHED",
        "assignerShortName": "VulnCheck",
        "dateReserved": "2026-09-01T23:24:15.911Z",
        "datePublished": "2026-09-02T00:37:51.655Z",
        "dateUpdated": "2026-09-02T00:37:51.655Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
                "shortName": "VulnCheck",
                "dateUpdated": "2026-09-02T00:37:51.655Z"
            },
            "datePublic": "2026-08-19T00:00:00.000Z",
            "title": "BookStack before 26.05.4 Stored XSS via Drawing Upload",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "BookStack before 26.05.4 contains a stored cross-site scripting vulnerability in the drawing upload endpoint that accepts unvalidated base64 content and stores it without content inspection. Attackers with editor permissions can upload SVG files containing scripts that execute in administrator browsers when accessed through the image gallery API without content-type validation or CSP headers."
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')",
                            "cweId": "CWE-79",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "bookstackapp",
                    "product": "bookstack",
                    "defaultStatus": "unaffected",
                    "packageURL": "pkg:github/BookStackApp/BookStack",
                    "versions": [
                        {
                            "version": "0",
                            "status": "affected",
                            "versionType": "custom",
                            "lessThan": "26.05.4"
                        },
                        {
                            "version": "26.05.4",
                            "status": "unaffected",
                            "versionType": "custom"
                        }
                    ],
                    "collectionURL": "https://github.com/BookStackApp/BookStack",
                    "repo": "https://github.com/BookStackApp/BookStack"
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:bookstackapp:bookstack:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "26.05.4"
                                }
                            ]
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "cvssV4_0": {
                        "version": "4.0",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N",
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "LOW",
                        "userInteraction": "PASSIVE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "HIGH",
                        "subIntegrityImpact": "HIGH",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 9.3,
                        "baseSeverity": "CRITICAL"
                    }
                },
                {
                    "format": "CVSS",
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "privilegesRequired": "LOW",
                        "userInteraction": "REQUIRED",
                        "scope": "CHANGED",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "availabilityImpact": "NONE",
                        "baseScore": 8.7,
                        "baseSeverity": "HIGH"
                    }
                }
            ],
            "references": [
                {
                    "url": "https://github.com/BookStackApp/BookStack",
                    "tags": [
                        "product"
                    ]
                },
                {
                    "url": "https://github.com/BookStackApp/BookStack/commit/ac0348a79f3ddd004ca87703948cb9c7d19a420a",
                    "tags": [
                        "patch"
                    ],
                    "name": "Patch Commit"
                },
                {
                    "url": "https://github.com/BookStackApp/BookStack/blob/v26.05.3/app/Uploads/ImageService.php",
                    "tags": [
                        "technical-description"
                    ]
                },
                {
                    "url": "https://github.com/BookStackApp/BookStack/releases/tag/v26.05.4",
                    "tags": [
                        "release-notes"
                    ],
                    "name": "BookStack v26.05.4 Release Notes"
                },
                {
                    "url": "https://www.bookstackapp.com/blog/bookstack-release-v26-05-4/",
                    "tags": [
                        "vendor-advisory"
                    ]
                },
                {
                    "name": "VulnCheck Advisory: BookStack before 26.05.4 Stored XSS via Drawing Upload",
                    "tags": [
                        "third-party-advisory"
                    ],
                    "url": "https://www.vulncheck.com/advisories/bookstack-before-26.05.4-stored-xss-via-drawing-upload"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Emanuele Cervelli",
                    "type": "finder"
                }
            ],
            "x_generator": {
                "engine": "vulncheck-endgame"
            }
        }
    }
}