{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-101878", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-09-28T15:44:45.389Z", "datePublished": "2026-09-29T01:58:32.484Z", "dateUpdated": "2026-10-01T19:19:18.222Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-10-01T19:19:18.222Z"}, "title": "Bitwarden Server 2025.6.0 < 2025.6.0 Authentication Bypass via SSO Identifier Truncation", "descriptions": [{"lang": "en", "value": "Bitwarden Server 2025.6.0 before 2026.5.0 declares the @ExternalId parameter of the User_ReadBySsoUserOrganizationIdExternalId stored procedure as NVARCHAR(50) while the column it queries stores NVARCHAR(300), silently truncating the SSO login identifier on SQL Server deployments and allowing a user whose identity-provider identifier begins with another organization member's full 50-character identifier to authenticate as that member and obtain a victim-scoped access token."}], "tags": ["x_open-source"], "datePublic": "2026-04-29T00:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-303", "description": "Incorrect Implementation of Authentication Algorithm", "type": "CWE"}]}], "affected": [{"defaultStatus": "unaffected", "vendor": "bitwarden", "product": "bitwarden server", "packageURL": "pkg:github/bitwarden/server", "repo": "https://github.com/bitwarden/server", "versions": [{"status": "affected", "version": "2025.6.0", "versionType": "custom", "lessThan": "2026.5.0"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*", "versionStartIncluding": "2025.6.0", "versionEndExcluding": "2026.5.0"}]}]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "HIGH", "baseScore": 7.7, "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}}], "references": [{"url": "https://sanjokkarki.com.np/blog/bitwarden-sso-externalid-truncation", "name": "Researcher Blog", "tags": ["technical-description", "exploit"]}, {"url": "https://github.com/bitwarden/server/releases/tag/v2026.5.0", "name": "Release Notes", "tags": ["release-notes"]}, {"url": "https://github.com/bitwarden/server/pull/7501", "name": "Pull Request", "tags": ["issue-tracking"]}, {"url": "https://github.com/bitwarden/server/commit/27ae3d5455f723975fac03819eaeba8710666bc4", "name": "Patch Commit", "tags": ["patch"]}, {"url": "https://www.vulncheck.com/advisories/bitwarden-server-authentication-bypass-via-sso-identifier-truncation", "tags": ["third-party-advisory"]}], "credits": [{"lang": "en", "value": "Sanjok Karki", "type": "finder"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "vulncheck"}, "x_gcve": [{"vulnId": "CVE-2026-101878", "recordType": "advisory"}]}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-29T17:21:45.867113Z", "id": "CVE-2026-101878", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-29T17:22:11.133Z"}}]}, "vulnerability-lookup:meta": {"epss": {"cve": "CVE-2026-101878", "date": "2026-10-20", "epss": "0.00258", "percentile": "0.1647"}, "nvd": "{\"cve\":{\"id\":\"CVE-2026-101878\",\"sourceIdentifier\":\"disclosure@vulncheck.com\",\"published\":\"2026-09-29T02:16:54.990\",\"lastModified\":\"2026-09-30T17:23:08.953\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Bitwarden Server 2025.6.0 before 2026.5.0 declares the @ExternalId parameter of the User_ReadBySsoUserOrganizationIdExternalId stored procedure as NVARCHAR(50) while the column it queries stores NVARCHAR(300), silently truncating the SSO login identifier on SQL Server deployments and allowing a user whose identity-provider identifier begins with another organization member's full 50-character identifier to authenticate as that member and obtain a victim-scoped access token.\"}],\"affected\":[{\"source\":\"disclosure@vulncheck.com\",\"affectedData\":[{\"vendor\":\"bitwarden\",\"product\":\"bitwarden server\",\"defaultStatus\":\"unaffected\",\"repo\":\"https://github.com/bitwarden/server\",\"packageURL\":\"pkg:github/bitwarden/server\",\"versions\":[{\"version\":\"2025.6.0\",\"lessThan\":\"2026.5.0\",\"versionType\":\"custom\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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\",\"baseScore\":7.7,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.6,\"impactScore\":5.9}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-09-29T17:21:45.867113Z\",\"id\":\"CVE-2026-101878\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-303\"}]}],\"references\":[{\"url\":\"https://github.com/bitwarden/server/commit/27ae3d5455f723975fac03819eaeba8710666bc4\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://github.com/bitwarden/server/pull/7501\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://github.com/bitwarden/server/releases/tag/v2026.5.0\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://sanjokkarki.com.np/blog/bitwarden-sso-externalid-truncation\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://www.vulncheck.com/advisories/bitwarden-server-authentication-bypass-via-sso-identifier-truncation\",\"source\":\"disclosure@vulncheck.com\"}]}}", "vulnrichment": {"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-101878\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-09-29T17:21:45.867113Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-09-29T17:21:57.658Z\"}}], \"cna\": {\"tags\": [\"x_open-source\"], \"title\": \"Bitwarden Server 2025.6.0 < 2025.6.0 Authentication Bypass via SSO Identifier Truncation\", \"source\": {\"discovery\": \"UNKNOWN\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Sanjok Karki\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 7.7, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"LOW\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}, {\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"repo\": \"https://github.com/bitwarden/server\", \"vendor\": \"bitwarden\", \"product\": \"bitwarden server\", \"versions\": [{\"status\": \"affected\", \"version\": \"2025.6.0\", \"lessThan\": \"2026.5.0\", \"versionType\": \"custom\"}], \"packageURL\": \"pkg:github/bitwarden/server\", \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2026-04-29T00:00:00.000Z\", \"references\": [{\"url\": \"https://sanjokkarki.com.np/blog/bitwarden-sso-externalid-truncation\", \"name\": \"Researcher Blog\", \"tags\": [\"technical-description\", \"exploit\"]}, {\"url\": \"https://github.com/bitwarden/server/releases/tag/v2026.5.0\", \"name\": \"Release Notes\", \"tags\": [\"release-notes\"]}, {\"url\": \"https://github.com/bitwarden/server/pull/7501\", \"name\": \"Pull Request\", \"tags\": [\"issue-tracking\"]}, {\"url\": \"https://github.com/bitwarden/server/commit/27ae3d5455f723975fac03819eaeba8710666bc4\", \"name\": \"Patch Commit\", \"tags\": [\"patch\"]}, {\"url\": \"https://www.vulncheck.com/advisories/bitwarden-server-authentication-bypass-via-sso-identifier-truncation\", \"tags\": [\"third-party-advisory\"]}], \"x_generator\": {\"engine\": \"vulncheck\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Bitwarden Server 2025.6.0 before 2026.5.0 declares the @ExternalId parameter of the User_ReadBySsoUserOrganizationIdExternalId stored procedure as NVARCHAR(50) while the column it queries stores NVARCHAR(300), silently truncating the SSO login identifier on SQL Server deployments and allowing a user whose identity-provider identifier begins with another organization member's full 50-character identifier to authenticate as that member and obtain a victim-scoped access token.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-303\", \"description\": \"Incorrect Implementation of Authentication Algorithm\"}]}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"2026.5.0\", \"versionStartIncluding\": \"2025.6.0\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"shortName\": \"VulnCheck\", \"dateUpdated\": \"2026-10-01T19:19:18.222Z\"}}}", "cveMetadata": "{\"cveId\": \"CVE-2026-101878\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-01T19:19:18.222Z\", \"dateReserved\": \"2026-09-28T15:44:45.389Z\", \"assignerOrgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"datePublished\": \"2026-09-29T01:58:32.484Z\", \"assignerShortName\": \"VulnCheck\"}", "dataType": "CVE_RECORD", "dataVersion": "5.2"}}}