{"id":"CVE-2026-27749","aliases":["EUVD-2026-9821","GHSA-w8px-r6g2-r3wp"],"status":"published","title":"Avira Internet Security System Speedup Insecure Deserialization","description":"Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\\\ProgramData using .NET BinaryFormatter without implementing input validation or deserialization safeguards. Because the file can be created or modified by a local user in default configurations, an attacker can supply a crafted serialized payload that is deserialized by the privileged process, resulting in arbitrary code execution as SYSTEM.","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00356,"percentile":0.29651,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-502"],"published":"2026-03-05T14:15:35Z","modified":"2026-06-17T10:27:37Z","products":[{"vendor":"avira","product":"internet_security"},{"vendor":"gen digital inc.","product":"avira internet security"}],"references":[{"url":"https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions","tags":["release-notes","Release Notes"]},{"url":"https://www.avira.com/en/internet-security","tags":["product","Product"]},{"url":"https://www.gendigital.com/us/en/contact-us/security-advisories/","tags":["vendor-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27749"},{"url":"https://blog.quarkslab.com/avira-deserialize-delete-and-escalate-the-proper-way-to-use-an-av.html"},{"url":"https://www.vulncheck.com/advisories/avira-internet-security-system-speedup-insecure-deserialization"},{"url":"https://www.gendigital.com/us/en/contact-us/security-advisories"},{"url":"https://github.com/advisories/GHSA-w8px-r6g2-r3wp"}],"sources":{"cve":[{"id":"CVE-2026-27749","title":"Avira Internet Security System Speedup Insecure Deserialization","description":"Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\\\ProgramData using .NET BinaryFormatter without implementing input validation or deserialization safeguards. Because the file can be created or modified by a local user in default configurations, an attacker can supply a crafted serialized payload that is deserialized by the privileged process, resulting in arbitrary code execution as SYSTEM.","status":"published","published":"2026-03-05T14:15:35.58Z","modified":"2026-04-01T14:38:16.632Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T14:19:48.826324Z"}],"euvd":[{"id":"EUVD-2026-9821","description":"Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\\\ProgramData using .NET BinaryFormatter without implementing input validation or deserialization safeguards. Because the file can be created or modified by a local user in default configurations, an attacker can supply a crafted serialized payload that is deserialized by the privileged process, resulting in arbitrary code execution as SYSTEM.","status":"published","published":"2026-03-05T14:15:35Z","modified":"2026-04-01T14:38:16Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T19:25:24.493801Z"}],"ghsa":[{"id":"GHSA-w8px-r6g2-r3wp","title":"Avira Internet Security contains a deserialization of untrusted data vulnerability in the System...","description":"Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\\\ProgramData using .NET BinaryFormatter without implementing input validation or deserialization safeguards. Because the file can be created or modified by a local user in default configurations, an attacker can supply a crafted serialized payload that is deserialized by the privileged process, resulting in arbitrary code execution as SYSTEM.","status":"published","published":"2026-03-05T15:30:36Z","modified":"2026-04-01T15:31:59Z","cvss":[{"version":"4.0","score":8.5,"vector":"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","level":"high"},{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T15:06:57.03617Z"}],"nvd":[{"id":"CVE-2026-27749","description":"Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\\\ProgramData using .NET BinaryFormatter without implementing input validation or deserialization safeguards. Because the file can be created or modified by a local user in default configurations, an attacker can supply a crafted serialized payload that is deserialized by the privileged process, resulting in arbitrary code execution as SYSTEM.","status":"published","published":"2026-03-05T15:16:11.963Z","modified":"2026-06-17T10:27:37.73Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T14:12:07.852448Z"}]}}