{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-27750", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-02-23T21:38:48.842Z", "datePublished": "2026-03-05T14:15:23.095Z", "dateUpdated": "2026-03-05T14:15:23.095Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "platforms": ["Windows"], "product": "Avira Internet Security", "vendor": "Gen Digital Inc.", "versions": [{"lessThanOrEqual": "1.1.109.1990", "status": "affected", "version": "0", "versionType": "semver"}]}], "credits": [{"lang": "en", "type": "finder", "value": "Quarkslab"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Avira Internet Security contains a time-of-check time-of-use (TOCTOU) vulnerability in the Optimizer component. A privileged service running as SYSTEM identifies directories for cleanup during a scan phase and subsequently deletes them during a separate cleanup phase without revalidating the target path. A local attacker can replace a previously scanned directory with a junction or reparse point before deletion occurs, causing the privileged process to delete an unintended system location. This may result in deletion of protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target."}], "value": "Avira Internet Security contains a time-of-check time-of-use (TOCTOU) vulnerability in the Optimizer component. A privileged service running as SYSTEM identifies directories for cleanup during a scan phase and subsequently deletes them during a separate cleanup phase without revalidating the target path. A local attacker can replace a previously scanned directory with a junction or reparse point before deletion occurs, causing the privileged process to delete an unintended system location. This may result in deletion of protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target."}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "baseScore": 8.5, "baseSeverity": "HIGH", "exploitMaturity": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-367", "description": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-03-05T14:15:23.095Z"}, "references": [{"tags": ["technical-description", "exploit"], "url": "https://blog.quarkslab.com/avira-deserialize-delete-and-escalate-the-proper-way-to-use-an-av.html"}, {"tags": ["release-notes"], "url": "https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions"}, {"tags": ["product"], "url": "https://www.avira.com/en/internet-security"}, {"tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/avira-internet-security-optimizer-toctou"}], "source": {"discovery": "UNKNOWN"}, "title": "Avira Internet Security Optimizer TOCTOU", "x_generator": {"engine": "Vulnogram 0.5.0"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "Avira Internet Security contains a time-of-check time-of-use (TOCTOU) vulnerability in the Optimizer component. A privileged service running as SYSTEM identifies directories for cleanup during a scan phase and subsequently deletes them during a separate cleanup phase without revalidating the target path. A local attacker can replace a previously scanned directory with a junction or reparse point before deletion occurs, causing the privileged process to delete an unintended system location. This may result in deletion of protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target."}, {"lang": "es", "value": "Avira Internet Security contiene una vulnerabilidad de tiempo de comprobaci\u00f3n y tiempo de uso (TOCTOU) en el componente Optimizer. Un servicio con privilegios que se ejecuta como SYSTEM identifica los directorios que deben limpiarse durante una fase de an\u00e1lisis y, posteriormente, los elimina durante una fase de limpieza independiente sin volver a validar la ruta de destino. Un atacante local puede sustituir un directorio escaneado previamente por un punto de uni\u00f3n o de rean\u00e1lisis antes de que se produzca la eliminaci\u00f3n, lo que provoca que el proceso con privilegios elimine una ubicaci\u00f3n del sistema no deseada. Esto puede dar lugar a la eliminaci\u00f3n de archivos o directorios protegidos y puede provocar una escalada de privilegios locales, una denegaci\u00f3n de servicio o un compromiso de la integridad del sistema, dependiendo del objetivo afectado."}], "id": "CVE-2026-27750", "lastModified": "2026-03-05T19:38:33.877", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.5, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-03-05T15:16:12.153", "references": [{"source": "disclosure@vulncheck.com", "url": "https://blog.quarkslab.com/avira-deserialize-delete-and-escalate-the-proper-way-to-use-an-av.html"}, {"source": "disclosure@vulncheck.com", "url": "https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions"}, {"source": "disclosure@vulncheck.com", "url": "https://www.avira.com/en/internet-security"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/avira-internet-security-optimizer-toctou"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-367"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

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