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."}],"impacts":[{"descriptions":[{"lang":"en","value":"A time-of-check to time-of-use condition allows a directory identified during scanning to be replaced with a junction or reparse point before a separate privileged deletion phase, redirecting deletion to an unintended location."}]},{"descriptions":[{"lang":"en","value":"Successful exploitation may delete protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target."}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"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":{"dateUpdated":"2026-04-01T14:38:35.968Z","orgId":"dbd8429d-f261-4b1e-94cc-ae3132817e2e","shortName":"GEN"},"references":[{"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":["vendor-advisory"],"url":"https://www.gendigital.com/us/en/contact-us/security-advisories/"}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Upgrade Avira Internet Security for Windows to version 1.1.114.3113 or later. Apply updates through the product's built-in updater or a fresh install from the vendor; see the release-notes reference in this record for current supported versions.
"}],"value":"Upgrade Avira Internet Security for Windows to version 1.1.114.3113 or later. Apply updates through the product's built-in updater or a fresh install from the vendor; see the release-notes reference in this record for current supported versions."}],"title":"Avira Internet Security Optimizer TOCTOU"}},"cveMetadata":{"assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","assignerShortName":"VulnCheck","cveId":"CVE-2026-27750","datePublished":"2026-03-05T14:15:23.095Z","dateReserved":"2026-02-23T21:38:48.842Z","dateUpdated":"2026-04-01T14:38:35.968Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-05 15:16:12","lastModifiedDate":"2026-04-01 15:22:36","problem_types":["CWE-367","CWE-367 CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition"],"metrics":{"cvssMetricV31":[{"source":"security@nortonlifelock.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1,"impactScore":5.9}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:avira:internet_security:*:*:*:*:*:windows:*:*","versionEndExcluding":"1.1.114.3113","matchCriteriaId":"DFB6EFB7-8777-4A9B-9A00-2FBEE12A7090"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"27750","Ordinal":"1","Title":"Avira Internet Security Optimizer TOCTOU","CVE":"CVE-2026-27750","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"27750","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Avira Internet Security Optimizer TOCTOU"}]}}}