CVE-2026-76877

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-76877", "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "state": "PUBLISHED", "assignerShortName": "Wordfence", "dateReserved": "2026-08-19T22:01:11.520Z", "datePublished": "2026-11-10T06:47:00.496Z", "dateUpdated": "2026-11-13T14:59:23.969Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "shortName": "Wordfence", "dateUpdated": "2026-11-11T14:52:59.092Z"}, "affected": [{"vendor": "WPML", "product": "WPML Multilingual CMS", "versions": [{"version": "0", "status": "affected", "lessThanOrEqual": "4.9.7", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "The WPML Multilingual CMS plugin for WordPress is vulnerable to Authentication Bypass via Race Condition in versions up to, and including, 4.9.7. This is due to the `process_iframe_request` function's language-per-domain SSO handler generating the cross-domain sign-in token via `wp_create_nonce('wpml_sso')` on the logout landing page, where the browser has already discarded its authentication cookies \u2014 so `wp_get_session_token()` returns an empty string and the token collapses to the shared anonymous nonce for the current 12-hour tick rather than a user-bound secret \u2014 and then storing it in the `wpml_sso_user_<token>_<sha256('wpml_sso'.$domain)>` transient mapped to the victim's `user_id` with no binding to the specific sign-out action or requesting client. Because an unauthenticated attacker can independently derive the identical token by triggering the logout confirmation flow on `wp-login.php?action=logout`, and because the `is_iframe_request()` gate conditions (the per-domain SSO `started` transient and domain-hash derived from the public constant `SSO_NONCE`) are fully computable within the 60-second `SSO_TIMEOUT` window, an unauthenticated attacker can submit the forged `wpml_sso_token_domain` parameter with a `wpml_user_signed_in` status to a secondary language-domain endpoint before the legitimate `wpml_user_signed_out` iframe fires, causing WordPress authentication cookies to be issued for the victim. This makes it possible for unauthenticated attackers to gain access to accounts of users \u2014 including administrators \u2014 who are actively in the process of logging out during the race window."}], "title": "WPML Multilingual CMS <= 4.9.7 - Unauthenticated Authentication Bypass in Language-per-Domain SSO via 'wpml_sso_token_domain' Parameter", "references": [{"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/006d1fcd-77b4-4214-be71-b6d71afad072?source=cve"}, {"url": "https://wpml.org/"}, {"url": "https://wpml.org/version/wpml-5-0-0/"}], "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:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.1, "baseSeverity": "HIGH"}}], "credits": [{"lang": "en", "type": "finder", "value": "Yuto Hyakumoto"}], "timeline": [{"time": "2026-08-19T22:33:04.000Z", "lang": "en", "value": "Vendor Notified"}, {"time": "2026-11-09T18:29:57.000Z", "lang": "en", "value": "Disclosed"}]}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-11-13T14:58:15.838219Z", "id": "CVE-2026-76877", "options": [{"Exploitation": "none"}, {"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": "2026-11-13T14:59:23.969Z"}}]}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "WPML Multilingual CMS", "vendor": "WPML", "versions": [{"lessThanOrEqual": "4.9.7", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "security@wordfence.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The WPML Multilingual CMS plugin for WordPress is vulnerable to Authentication Bypass via Race Condition in versions up to, and including, 4.9.7. This is due to the `process_iframe_request` function's language-per-domain SSO handler generating the cross-domain sign-in token via `wp_create_nonce('wpml_sso')` on the logout landing page, where the browser has already discarded its authentication cookies \u2014 so `wp_get_session_token()` returns an empty string and the token collapses to the shared anonymous nonce for the current 12-hour tick rather than a user-bound secret \u2014 and then storing it in the `wpml_sso_user_<token>_<sha256('wpml_sso'.$domain)>` transient mapped to the victim's `user_id` with no binding to the specific sign-out action or requesting client. Because an unauthenticated attacker can independently derive the identical token by triggering the logout confirmation flow on `wp-login.php?action=logout`, and because the `is_iframe_request()` gate conditions (the per-domain SSO `started` transient and domain-hash derived from the public constant `SSO_NONCE`) are fully computable within the 60-second `SSO_TIMEOUT` window, an unauthenticated attacker can submit the forged `wpml_sso_token_domain` parameter with a `wpml_user_signed_in` status to a secondary language-domain endpoint before the legitimate `wpml_user_signed_out` iframe fires, causing WordPress authentication cookies to be issued for the victim. This makes it possible for unauthenticated attackers to gain access to accounts of users \u2014 including administrators \u2014 who are actively in the process of logging out during the race window."}], "id": "CVE-2026-76877", "lastModified": "2026-11-13T15:17:56.223", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "security@wordfence.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-76877", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-11-13T14:58:15.838219Z", "version": "2.0.3"}}]}, "published": "2026-11-10T07:16:52.463", "references": [{"source": "security@wordfence.com", "url": "https://wpml.org/"}, {"source": "security@wordfence.com", "url": "https://wpml.org/version/wpml-5-0-0/"}, {"source": "security@wordfence.com", "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/006d1fcd-77b4-4214-be71-b6d71afad072?source=cve"}], "sourceIdentifier": "security@wordfence.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-287"}], "source": "security@wordfence.com", "type": "Secondary"}]}

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