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Internet SecurityApplication · Avira

CVE-2026-27748

HIGH · 7.1 CVSS v3.1 Published 2026-03-05
Fix available
A fix is available. Upgrade to 1.1.114.3113 or later.
See remediation →
73/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Avira Internet Security contains an improper link resolution vulnerability in the Software Updater component. During the update process, a privileged service running as SYSTEM deletes a file under C:\\ProgramData without validating whether the path resolves through a symbolic link or reparse point. A local attacker can create a malicious link to redirect the delete operation to an arbitrary file, resulting in deletion of attacker-chosen files with SYSTEM privileges. This may lead to local privilege escalation, denial of service, or system integrity compromise depending on the targeted file and operating system configuration.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Avira Internet Security Software Updater runs a privileged service as SYSTEM that deletes files under C:\ProgramData without validating whether the file path traverses a symbolic link or reparse point. A local attacker can create a malicious symlink to redirect the delete operation to arbitrary files, achieving deletion with SYSTEM privileges.

MitigationImplement atomic link resolution checks (e.g., using FILE_FLAG_OPEN_REPARSE_POINT and verifying the final path doesn't traverse links) before file deletion operations in the Software Updater component.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Internet SecurityApplication
Affected:< 1.1.114.3113

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Avira Internet Security is installed
    Open Programs and Features (appwiz.cpl) or check C:\Program Files\Avira for the installation directory
    Affected if Avira Internet Security is present on the system
  2. Identify the installed version
    Check the version in the Software Updater component or in the main Avira installation: look at the version info in the Avira Internet Security program folder or in the registry under HKLM\SOFTWARE\Avira
    Affected if The version number is lower than 1.1.114.3113
  3. Verify the Software Updater service exists and runs
    Open Services (services.msc) and look for a service related to Avira Software Updater, or check for the updater process running under SYSTEM
    Affected if The Software Updater service is present and running as SYSTEM
  4. Check if the service has write access to C:\ProgramData
    Inspect permissions on C:\ProgramData to see if non-privileged users can create files or symlinks in this directory
    Affected if Standard users can create symbolic links or files in C:\ProgramData that the Software Updater might process

The system is affected if Avira Internet Security with Software Updater is installed with a version below 1.1.114.3113 and the updater service runs as SYSTEM with access to C:\ProgramData.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.1.114.3113 or later
Fixed in 1.1.114.3113
Interim mitigation

Implement atomic link resolution checks (e.g., using FILE_FLAG_OPEN_REPARSE_POINT and verifying the final path doesn't traverse links) before file deletion operations in the Software Updater component.

Recommended fix High confidence

Avira Internet Security version 1.1.114.3113 or later

  1. 1. Open Avira Internet Security application
  2. 2. Navigate to the Help & Settings or About section
  3. 3. Check the current version of Avira Internet Security
  4. 4. If version is below 1.1.114.3113, initiate the update process
  5. 5. Alternatively, download the latest version from the official Avira website (www.avira.com)
  6. 6. Run the installer and follow the prompts to complete the upgrade
  7. 7. Restart the system if prompted
  8. 8. Verify the installed version is 1.1.114.3113 or higher

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Internet Security Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27748 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data