Vulnerability-Lookup

GHSA-W8PX-R6G2-R3WP

Vulnerability from github – Published: 2026-03-05 15:30 – Updated: 2026-04-01 15:30

Details

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

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

8.5 (High)


                  
                    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

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  "affected": [],
  "aliases": [
    "CVE-2026-27749"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-05T15:16:11Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-w8px-r6g2-r3wp",
  "modified": "2026-04-01T15:30:56Z",
  "published": "2026-03-05T15:30:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27749"
    },
    {
      "type": "WEB",
      "url": "https://blog.quarkslab.com/avira-deserialize-delete-and-escalate-the-proper-way-to-use-an-av.html"
    },
    {
      "type": "WEB",
      "url": "https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions"
    },
    {
      "type": "WEB",
      "url": "https://www.avira.com/en/internet-security"
    },
    {
      "type": "WEB",
      "url": "https://www.gendigital.com/us/en/contact-us/security-advisories"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/avira-internet-security-system-speedup-insecure-deserialization"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-27749 (GCVE-0-2026-27749)

Vulnerability from cvelistv5 – Published: 2026-03-05 14:15 – Updated: 2026-04-01 14:38

Title

Avira Internet Security System Speedup Insecure Deserialization

Summary

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

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-06 18:17 UTC

CWE

CWE-502 - Deserialization of Untrusted Data

Assigner

VulnCheck mitre root

References

3 references

URL	Tags
https://support.avira.com/hc/en-us/articles/36001…	release-notes
https://www.avira.com/en/internet-security	product
https://www.gendigital.com/us/en/contact-us/secur…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
Gen Digital Inc.	Avira Internet Security	Affected: 0 , ≤ 1.1.109.1990 (semver) Unaffected: 1.1.114.3113 (semver) cpe:2.3:a:avira:avira_internet_security_suite::::::windows::*

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JSON

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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GHSA-W8PX-R6G2-R3WP

CVE-2026-27749 (GCVE-0-2026-27749)

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