{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-15341", "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "state": "PUBLISHED", "assignerShortName": "Wordfence", "dateReserved": "2026-07-09T20:00:20.994Z", "datePublished": "2026-08-15T02:26:17.894Z", "dateUpdated": "2026-08-15T02:26:17.894Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "shortName": "Wordfence", "dateUpdated": "2026-08-15T02:26:17.894Z"}, "affected": [{"vendor": "rafasashi", "product": "User Session Synchronizer", "versions": [{"version": "0", "status": "affected", "lessThanOrEqual": "1.4.0", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "The User Session Synchronizer plugin for WordPress is vulnerable to Authentication Bypass leading to Account Takeover in all versions up to, and including, 1.4.0. The `synchronize_session()` function, hooked on `init` and therefore executed on every request, performs no nonce, capability, or shared-secret validation against the attacker-supplied `ussync-key`, `ussync-token`, and `ussync-ref` parameters; when `ussync-key` references an unregistered slot, `get_option()` returns `false` for both the secret key and the domain list, causing the AES-256-CBC encryption key to degrade to the fully predictable `md5('')` and the referer allowlist to collapse to an empty-string match, while the AES IV is unconditionally hard-coded as `md5('another-secret')`. This makes it possible for unauthenticated attackers to supply a crafted request encrypting any known or guessable user email address in the `ussync-ref` parameter, causing the handler to call `wp_set_auth_cookie()` for the matched user and granting full authentication as that user \u2014 including administrators \u2014 with no prior knowledge of site secrets."}], "title": "User Session Synchronizer <= 1.4.0 - Unauthenticated Authentication Bypass to Account Takeover via 'ussync-key', 'ussync-token', and 'ussync-ref' Parameters", "references": [{"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/cbc32e6d-47c5-4050-ba77-5a54203fe56a?source=cve"}, {"url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L422"}, {"url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L117"}, {"url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L286"}, {"url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L310"}, {"url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L631"}, {"url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L598"}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-287 Improper Authentication", "cweId": "CWE-287", "type": "CWE"}]}], "metrics": [{"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", "baseScore": 9.8, "baseSeverity": "CRITICAL"}}], "credits": [{"lang": "en", "type": "finder", "value": "Afan"}, {"lang": "en", "type": "finder", "value": "moonge"}], "timeline": [{"time": "2026-08-14T14:02:18.000Z", "lang": "en", "value": "Disclosed"}]}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "User Session Synchronizer", "vendor": "rafasashi", "versions": [{"lessThanOrEqual": "1.4.0", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "security@wordfence.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The User Session Synchronizer plugin for WordPress is vulnerable to Authentication Bypass leading to Account Takeover in all versions up to, and including, 1.4.0. The `synchronize_session()` function, hooked on `init` and therefore executed on every request, performs no nonce, capability, or shared-secret validation against the attacker-supplied `ussync-key`, `ussync-token`, and `ussync-ref` parameters; when `ussync-key` references an unregistered slot, `get_option()` returns `false` for both the secret key and the domain list, causing the AES-256-CBC encryption key to degrade to the fully predictable `md5('')` and the referer allowlist to collapse to an empty-string match, while the AES IV is unconditionally hard-coded as `md5('another-secret')`. This makes it possible for unauthenticated attackers to supply a crafted request encrypting any known or guessable user email address in the `ussync-ref` parameter, causing the handler to call `wp_set_auth_cookie()` for the matched user and granting full authentication as that user \u2014 including administrators \u2014 with no prior knowledge of site secrets."}], "id": "CVE-2026-15341", "lastModified": "2026-08-15T03:16:47.943", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "security@wordfence.com", "type": "Primary"}]}, "published": "2026-08-15T03:16:47.943", "references": [{"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L117"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L286"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L310"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L422"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L598"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/user-session-synchronizer/tags/1.4.0/includes/class-user-session-synchronizer.php#L631"}, {"source": "security@wordfence.com", "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/cbc32e6d-47c5-4050-ba77-5a54203fe56a?source=cve"}], "sourceIdentifier": "security@wordfence.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-287"}], "source": "security@wordfence.com", "type": "Primary"}]}

{}

{"created": "2026-08-15T03:30:01.842222+00:00", "updated": "2026-08-15T03:30:01.842229+00:00", "vendors": []}