CVE-2026-39386

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-39386", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-04-06T22:06:40.515Z", "datePublished": "2026-04-21T00:50:34.656Z", "dateUpdated": "2026-04-22T03:56:19.795Z"}, "containers": {"cna": {"title": "Neko has Self-service Privilege Escalation for Authenticated Users", "problemTypes": [{"descriptions": [{"cweId": "CWE-20", "lang": "en", "description": "CWE-20: Improper Input Validation", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-269", "lang": "en", "description": "CWE-269: Improper Privilege Management", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-284", "lang": "en", "description": "CWE-284: Improper Access Control", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-639", "lang": "en", "description": "CWE-639: Authorization Bypass Through User-Controlled Key", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-862", "lang": "en", "description": "CWE-862: Missing Authorization", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/m1k1o/neko/security/advisories/GHSA-2gw9-c2r2-f5qf", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/m1k1o/neko/security/advisories/GHSA-2gw9-c2r2-f5qf"}, {"name": "https://github.com/m1k1o/neko/releases/tag/v3.0.11", "tags": ["x_refsource_MISC"], "url": "https://github.com/m1k1o/neko/releases/tag/v3.0.11"}, {"name": "https://github.com/m1k1o/neko/releases/tag/v3.1.2", "tags": ["x_refsource_MISC"], "url": "https://github.com/m1k1o/neko/releases/tag/v3.1.2"}], "affected": [{"vendor": "m1k1o", "product": "neko", "versions": [{"version": ">= 3.0.0, < 3.0.11", "status": "affected"}, {"version": ">= 3.1.0, < 3.1.2", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-04-21T00:50:34.656Z"}, "descriptions": [{"lang": "en", "value": "Neko is a a self-hosted virtual browser that runs in Docker and uses WebRTC In versions 3.0.0 through 3.0.10 and 3.1.0 through 3.1.1, any authenticated user can immediately obtain full administrative control of the entire Neko instance (member management, room settings, broadcast control, session termination, etc.). This results in a complete compromise of the instance. The vulnerability has been patched in v3.0.11 and v3.1.2. If upgrading is not immediately possible, the following mitigations can reduce risk: Restrict access to trusted users only (avoid granting accounts to untrusted parties); ensure all user passwords are strong and only shared with trusted individuals; run the instance only when needed; avoid leaving it continuously exposed; place the instance behind authentication layers such as a reverse proxy with additional access controls; disable or restrict access to the /api/profile endpoint if feasible; and/or monitor for suspicious privilege changes or unexpected administrative actions. Note that these are temporary mitigations and do not fully eliminate the vulnerability. Upgrading is strongly recommended."}], "source": {"advisory": "GHSA-2gw9-c2r2-f5qf", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-04-21T00:00:00+00:00", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2026-39386"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-22T03:56:19.795Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-39386", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-04-21T13:33:45.762826Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-21T13:33:50.593Z"}}], "cna": {"title": "Neko has Self-service Privilege Escalation for Authenticated Users", "source": {"advisory": "GHSA-2gw9-c2r2-f5qf", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}], "affected": [{"vendor": "m1k1o", "product": "neko", "versions": [{"status": "affected", "version": ">= 3.0.0, < 3.0.11"}, {"status": "affected", "version": ">= 3.1.0, < 3.1.2"}]}], "references": [{"url": "https://github.com/m1k1o/neko/security/advisories/GHSA-2gw9-c2r2-f5qf", "name": "https://github.com/m1k1o/neko/security/advisories/GHSA-2gw9-c2r2-f5qf", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/m1k1o/neko/releases/tag/v3.0.11", "name": "https://github.com/m1k1o/neko/releases/tag/v3.0.11", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/m1k1o/neko/releases/tag/v3.1.2", "name": "https://github.com/m1k1o/neko/releases/tag/v3.1.2", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "Neko is a a self-hosted virtual browser that runs in Docker and uses WebRTC In versions 3.0.0 through 3.0.10 and 3.1.0 through 3.1.1, any authenticated user can immediately obtain full administrative control of the entire Neko instance (member management, room settings, broadcast control, session termination, etc.). This results in a complete compromise of the instance. The vulnerability has been patched in v3.0.11 and v3.1.2. If upgrading is not immediately possible, the following mitigations can reduce risk: Restrict access to trusted users only (avoid granting accounts to untrusted parties); ensure all user passwords are strong and only shared with trusted individuals; run the instance only when needed; avoid leaving it continuously exposed; place the instance behind authentication layers such as a reverse proxy with additional access controls; disable or restrict access to the /api/profile endpoint if feasible; and/or monitor for suspicious privilege changes or unexpected administrative actions. Note that these are temporary mitigations and do not fully eliminate the vulnerability. Upgrading is strongly recommended."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-20", "description": "CWE-20: Improper Input Validation"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-269", "description": "CWE-269: Improper Privilege Management"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-284", "description": "CWE-284: Improper Access Control"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-639", "description": "CWE-639: Authorization Bypass Through User-Controlled Key"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-862", "description": "CWE-862: Missing Authorization"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-04-21T00:50:34.656Z"}}}, "cveMetadata": {"cveId": "CVE-2026-39386", "state": "PUBLISHED", "dateUpdated": "2026-04-22T03:56:19.795Z", "dateReserved": "2026-04-06T22:06:40.515Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-04-21T00:50:34.656Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "neko", "vendor": "m1k1o", "versions": [{"status": "affected", "version": ">= 3.0.0, < 3.0.11"}, {"status": "affected", "version": ">= 3.1.0, < 3.1.2"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:m1k1o:neko:*:*:*:*:*:*:*:*", "matchCriteriaId": "58BE7A22-09E6-4816-92B2-068D5BA33669", "versionEndExcluding": "3.0.11", "versionStartIncluding": "3.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:m1k1o:neko:*:*:*:*:*:*:*:*", "matchCriteriaId": "9C19A8F7-3E62-4599-B3DF-FA374D5F4F8A", "versionEndExcluding": "3.1.2", "versionStartIncluding": "3.1.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Neko is a a self-hosted virtual browser that runs in Docker and uses WebRTC In versions 3.0.0 through 3.0.10 and 3.1.0 through 3.1.1, any authenticated user can immediately obtain full administrative control of the entire Neko instance (member management, room settings, broadcast control, session termination, etc.). This results in a complete compromise of the instance. The vulnerability has been patched in v3.0.11 and v3.1.2. If upgrading is not immediately possible, the following mitigations can reduce risk: Restrict access to trusted users only (avoid granting accounts to untrusted parties); ensure all user passwords are strong and only shared with trusted individuals; run the instance only when needed; avoid leaving it continuously exposed; place the instance behind authentication layers such as a reverse proxy with additional access controls; disable or restrict access to the /api/profile endpoint if feasible; and/or monitor for suspicious privilege changes or unexpected administrative actions. Note that these are temporary mitigations and do not fully eliminate the vulnerability. Upgrading is strongly recommended."}, {"lang": "es", "value": "Neko es un navegador virtual autoalojado que se ejecuta en Docker y utiliza WebRTC. En las versiones 3.0.0 a 3.0.10 y 3.1.0 a 3.1.1, cualquier usuario autenticado puede obtener inmediatamente control administrativo total de toda la instancia de Neko (gesti\u00f3n de miembros, configuraci\u00f3n de sala, control de transmisi\u00f3n, terminaci\u00f3n de sesi\u00f3n, etc.). Esto resulta en un compromiso completo de la instancia. La vulnerabilidad ha sido parcheada en v3.0.11 y v3.1.2. Si la actualizaci\u00f3n no es inmediatamente posible, las siguientes mitigaciones pueden reducir el riesgo: Restringir el acceso solo a usuarios de confianza (evitar conceder cuentas a partes no confiables); asegurar que todas las contrase\u00f1as de usuario sean fuertes y solo se compartan con individuos de confianza; ejecutar la instancia solo cuando sea necesario; evitar dejarla continuamente expuesta; colocar la instancia detr\u00e1s de capas de autenticaci\u00f3n como un proxy inverso con controles de acceso adicionales; deshabilitar o restringir el acceso al endpoint /api/profile si es factible; y/o monitorear cambios de privilegios sospechosos o acciones administrativas inesperadas. Tenga en cuenta que estas son mitigaciones temporales y no eliminan completamente la vulnerabilidad. Se recomienda encarecidamente la actualizaci\u00f3n."}], "id": "CVE-2026-39386", "lastModified": "2026-10-26T22:10:00.163", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.9, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-39386", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-04-21T00:00:00+00:00", "version": "2.0.3"}}]}, "published": "2026-04-21T01:16:06.217", "references": [{"source": "security-advisories@github.com", "tags": ["Product"], "url": "https://github.com/m1k1o/neko/releases/tag/v3.0.11"}, {"source": "security-advisories@github.com", "tags": ["Product"], "url": "https://github.com/m1k1o/neko/releases/tag/v3.1.2"}, {"source": "security-advisories@github.com", "tags": ["Mitigation", "Vendor Advisory"], "url": "https://github.com/m1k1o/neko/security/advisories/GHSA-2gw9-c2r2-f5qf"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-269"}, {"lang": "en", "value": "CWE-284"}, {"lang": "en", "value": "CWE-639"}, {"lang": "en", "value": "CWE-862"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.0.0,3.0.11)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.1.0,3.1.2)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "neko", "source": "cna", "vendor": "m1k1o"}, "product": "neko", "vendor": "m1k1o"}], "analysis": {"en": {"generated_at": "2026-04-21T15:32:14.883246+00:00", "value": {"mitigation_remediation": ["Apply the latest patch by upgrading Neko to version 3.0.11 or later, including 3.1.2 and beyond.", "If an immediate upgrade is not possible, limit the instance to trusted users only, enforce strong, unique passwords, and run the service only when necessary.", "Deploy the instance behind a reverse proxy with additional access controls, disable or tightly restrict access to the /api/profile endpoint, and monitor for unauthorized privilege changes or unexpected administrative actions."], "summary": {"action": "Urgent Patch", "impact": "Privilege Escalation"}, "threat_synthesis": {"affected_systems": "The affected product is Neko from m1k1o. Versions 3.0.0 through 3.0.10 and 3.1.0 through 3.1.1 are vulnerable. The issue has been patched in releases v3.0.11 and v3.1.2.", "description_and_impact": "Neko, a self-hosted virtual browser, has a flaw that lets any authenticated user gain full administrative control over the entire instance, including member management, room settings, broadcast control, and session termination. This gives the attacker complete compromise of the instance. The weakness is reflected in multiple CWE identifiers, such as unchecked input (CWE\u201120) and missing access control (CWE\u2011269, CWE\u2011284, CWE\u2011639, CWE\u2011862).", "risk_and_exploitability": "The CVSS score of 8.8 indicates a high severity vulnerability. The exploit requires only a legitimate authenticated session; an attacker who can log in can perform privileged operations via the web interface or API. Although no EPSS score is available and it is not listed in the CISA KEV catalog, the impact of a successful exploit is total administrative takeover of the instance. Because the vulnerability is driven by the attacker\u2019s credential, the attack vector is likely evaluated as authenticated. Typical environments that expose Neko to the public internet face a higher risk, especially if weak or shared passwords, or unrestricted reverse proxies, are present."}}}}, "created": "2026-04-21T15:37:55.178240+00:00", "updated": "2026-04-22T11:47:00.236357+00:00", "vendors": ["m1k1o", "m1k1o$PRODUCT$neko"]}