CVE-2026-39924
Full vulnerability record from the local CVENow database.
Description
Flarum before 1.8.16 contains an improper session invalidation vulnerability that allows attackers who hold a valid session token to retain full account access after a victim changes their password, because the access_tokens table is never cleared on password change events. The TokensClearer::clearPasswordTokens() function only removes rows from the password_tokens table while leaving all active session cookies and API bearer tokens intact, including long-lived RememberAccessToken entries, and administrator-forced password resets via the user update endpoint are equally ineffective at revoking attacker-held sessions.
Severity
HIGH
CVSS score
7.6
(v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-08-05 16:16:56.137000
Last modified
2026-10-23 21:10:00.157000
View original CVE JSON
{
"id": "CVE-2026-39924",
"sourceIdentifier": "[email protected]",
"published": "2026-08-05T16:16:56.137",
"lastModified": "2026-10-23T21:10:00.157",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Flarum before 1.8.16 contains an improper session invalidation vulnerability that allows attackers who hold a valid session token to retain full account access after a victim changes their password, because the access_tokens table is never cleared on password change events. The TokensClearer::clearPasswordTokens() function only removes rows from the password_tokens table while leaving all active session cookies and API bearer tokens intact, including long-lived RememberAccessToken entries, and administrator-forced password resets via the user update endpoint are equally ineffective at revoking attacker-held sessions."
},
{
"lang": "es",
"value": "Flarum antes de 1.8.16 contiene una vulnerabilidad de invalidación de sesión impropia que permite a los atacantes que poseen un token de sesión válido retener acceso completo a la cuenta después de que una víctima cambia su contraseña, porque la tabla access_tokens nunca se borra en los eventos de cambio de contraseña. La función TokensClearer::clearPasswordTokens() solo elimina filas de la tabla password_tokens mientras deja intactas todas las cookies de sesión activas y los tokens portadores de API, incluidas las entradas RememberAccessToken de larga duración, y los restablecimientos de contraseña forzados por el administrador a través del endpoint de actualización de usuario son igualmente ineficaces para revocar las sesiones en poder del atacante."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Flarum",
"product": "Flarum Framework",
"defaultStatus": "affected",
"repo": "https://github.com/flarum/framework",
"packageURL": "pkg:github/flarum/framework",
"versions": [
{
"version": "0",
"lessThan": "1.8.16",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"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:N/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": 7.6,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"attackRequirements": "NONE",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnAvailabilityImpact": "NONE",
"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": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
"baseScore": 6.8,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 1.6,
"impactScore": 5.2
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-08-05T15:48:45.636552Z",
"id": "CVE-2026-39924",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-613"
}
]
}
],
"references": [
{
"url": "https://github.com/flarum/framework/commit/5f080293a029d0d273eb9678d597c74ea86a3bcc",
"source": "[email protected]"
},
{
"url": "https://github.com/flarum/framework/pull/4546",
"source": "[email protected]"
},
{
"url": "https://github.com/flarum/framework/releases/tag/v1.8.16",
"source": "[email protected]"
},
{
"url": "https://www.vulncheck.com/advisories/flarum-session-persistence-via-improper-access-token-revocation",
"source": "[email protected]"
}
]
}