{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-56765", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-06-22T21:55:17.942Z", "datePublished": "2026-07-10T13:57:59.648Z", "dateUpdated": "2026-07-10T13:57:59.648Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-07-10T13:57:59.648Z"}, "datePublic": "2026-03-23T00:00:00.000Z", "title": "Vikunja - Unauthenticated Instance-Wide Data Breach via Link Share Hash Disclosure Chained with Cross-Project Attachment IDOR", "descriptions": [{"lang": "en", "value": "Vikunja before 2.2.1 contains an authorization flaw where the LinkSharing.ReadAll endpoint exposes share hashes to users with read access, enabling permission escalation to admin-level shares. The GetTaskAttachment endpoint performs permission checks against user-supplied task IDs but fetches attachments by sequential ID without verifying ownership, allowing attackers to download and delete all file attachments across all projects instance-wide."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Authorization Bypass Through User-Controlled Key", "cweId": "CWE-639", "type": "CWE"}]}], "affected": [{"vendor": "Vikunja", "product": "Vikunja", "defaultStatus": "unaffected", "packageURL": "pkg:golang/code.vikunja.io/api", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThan": "2.2.1"}, {"version": "2.2.1", "status": "unaffected", "versionType": "semver"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.2.1"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 9.3, "baseSeverity": "CRITICAL"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL"}}], "references": [{"url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-2pv8-4c52-mf8j", "name": "GitHub Security Advisory (GHSA-2pv8-4c52-mf8j)", "tags": ["vendor-advisory"]}, {"name": "VulnCheck Advisory: Vikunja - Unauthenticated Instance-Wide Data Breach via Link Share Hash Disclosure Chained with Cross-Project Attachment IDOR", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/vikunja-unauthenticated-instance-wide-data-breach-via-link-share-hash-disclosure-chained-with-cross-project-attachment-idor"}], "credits": [{"lang": "en", "value": "offset", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.2.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "2.2.1"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "product": "vikunja", "vendor": "vikunja"}], "created": "2026-07-10T15:30:16.836083+00:00", "updated": "2026-07-10T15:30:16.836113+00:00", "vendors": ["vikunja", "vikunja$PRODUCT$vikunja"]}