{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-91981", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-09-15T11:10:41.353Z", "datePublished": "2026-09-15T15:18:25.523Z", "dateUpdated": "2026-09-15T15:18:25.523Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-09-15T15:18:25.523Z"}, "datePublic": "2026-08-31T00:00:00.000Z", "title": "Vikunja before 2.6.0 User Enumeration via v2 API", "descriptions": [{"lang": "en", "value": "Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Exposure of Sensitive Information to an Unauthorized Actor", "cweId": "CWE-200", "type": "CWE"}]}], "affected": [{"vendor": "go-vikunja", "product": "vikunja", "defaultStatus": "unaffected", "packageURL": "pkg:golang/code.vikunja.io/api", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThan": "2.6.0"}, {"version": "2.6.0", "status": "unaffected", "versionType": "semver"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.6.0"}]}]}], "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE", "baseScore": 4.3, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vfxw-3x8p-2vjr", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-vfxw-3x8p-2vjr)"}, {"name": "VulnCheck Advisory: Vikunja before 2.6.0 User Enumeration via v2 API", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/vikunja-before-2.6.0-user-enumeration-via-v2-api"}], "credits": [{"lang": "en", "value": "0xcelien", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

{}

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{}

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