{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-107585", "assignerOrgId": "ceab7361-8a18-47b1-92ba-4d7d25f6715a", "state": "PUBLISHED", "assignerShortName": "GitLab", "dateReserved": "2026-10-08T10:52:30.638Z", "datePublished": "2026-10-08T15:11:19.477Z", "dateUpdated": "2026-10-08T15:11:19.477Z"}, "containers": {"cna": {"title": "Allocation of Resources Without Limits or Throttling in hMailServer", "descriptions": [{"lang": "en", "value": "Uncontrolled eviction in the pending sign-in tables of the REST API in Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to make other users' OpenID Connect, SAML and passkey sign-ins fail. The routes that start a single sign-on and hand out a passkey sign-in challenge are reached without authentication and stored pending state in bounded tables that dropped their oldest entry when full, whoever had started it. An attacker who starts sign-ins a few times a second (about a hundred a second for passkeys) pushes every other user's pending sign-in out of the table before that user's browser returns, denying single sign-on and passkey sign-in for as long as the requests continue."}], "affected": [{"vendor": "Progressive Robot Ltd", "product": "hMailServer", "repo": "https://gitlab.com/hmailserver/hmailserver", "versions": [{"version": "6.3.4", "status": "affected", "lessThan": "6.3.6", "versionType": "semver"}], "defaultStatus": "unaffected"}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-770: Allocation of Resources Without Limits or Throttling", "cweId": "CWE-770", "type": "CWE"}]}], "references": [{"url": "https://gitlab.com/hmailserver/hmailserver/-/work_items/63"}, {"url": "https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM"}}], "solutions": [{"lang": "en", "value": "Upgrade to hMailServer 6.3.6, in which a pending OpenID Connect, SAML or passkey sign-in is no longer held on the server at all but carried by the browser in a cookie sealed with AES-256-GCM under a key held only in memory and good once, so there is no table a flood of unauthenticated starts can fill. Until then: limit the rate of /portal/oidc/start, /portal/saml/start and /api/v1/passkeys/challenge per client at a reverse proxy, and keep password sign-in available for administrators."}], "credits": [{"lang": "en", "value": "Found in the hMailServer project's own security review (Progressive Robot Ltd)", "type": "finder"}], "providerMetadata": {"orgId": "ceab7361-8a18-47b1-92ba-4d7d25f6715a", "shortName": "GitLab", "dateUpdated": "2026-10-08T15:11:19.477Z"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "hMailServer", "repo": "https://gitlab.com/hmailserver/hmailserver", "vendor": "Progressive Robot Ltd", "versions": [{"lessThan": "6.3.6", "status": "affected", "version": "6.3.4", "versionType": "semver"}]}], "source": "cve@gitlab.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Uncontrolled eviction in the pending sign-in tables of the REST API in Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to make other users' OpenID Connect, SAML and passkey sign-ins fail. The routes that start a single sign-on and hand out a passkey sign-in challenge are reached without authentication and stored pending state in bounded tables that dropped their oldest entry when full, whoever had started it. An attacker who starts sign-ins a few times a second (about a hundred a second for passkeys) pushes every other user's pending sign-in out of the table before that user's browser returns, denying single sign-on and passkey sign-in for as long as the requests continue."}], "id": "CVE-2026-107585", "lastModified": "2026-10-08T15:17:44.763", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "cve@gitlab.com", "type": "Secondary"}]}, "published": "2026-10-08T15:17:44.763", "references": [{"source": "cve@gitlab.com", "url": "https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.6"}, {"source": "cve@gitlab.com", "url": "https://gitlab.com/hmailserver/hmailserver/-/work_items/63"}], "sourceIdentifier": "cve@gitlab.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-770"}], "source": "cve@gitlab.com", "type": "Primary"}]}

{}

{}