HomeIntelligenceBrief
🛡️ VULNERABILITY BRIEF🟠 High🛡️ Vulnerability

Local Privilege Escalation in Avast Premium Security (CVE‑2026‑5424) Threatens Endpoint Integrity

A critical flaw (CVE‑2026‑5424) in Avast Premium Security's Gen Self‑Protection driver lets a low‑privileged attacker gain SYSTEM rights. The vulnerability affects all pre‑26.3 installations and can undermine endpoint defenses across multiple industries.

🛡️ LiveThreat™ Intelligence · 📅 April 16, 2026· 📰 zerodayinitiative.com
🟠
Severity
High
🛡️
Type
Vulnerability
🎯
Confidence
High
🏢
Affected
2 sector(s)
Actions
5 recommended
📰
Source
zerodayinitiative.com

Local Privilege Escalation in Avast Premium Security (CVE‑2026‑5424) Threatens Endpoint Integrity

What It Is – A newly disclosed vulnerability (CVE‑2026‑5424) in the Gen Self‑Protection driver of Avast Premium Security allows a local attacker to invoke an exposed dangerous function and elevate privileges to SYSTEM.

Exploitability – The flaw is locally exploitable once an adversary can run low‑privileged code. No public exploit code has been released, but the CVSS 7.8 rating (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) indicates a high likelihood of successful exploitation in the wild.

Affected Products – Avast Premium Security (all versions prior to 26.3).

TPRM Impact – The driver runs with kernel‑level rights; a compromise can bypass the very security controls an organization relies on, potentially giving attackers unfettered access to corporate networks, data stores, and other third‑party services.

Recommended Actions

  • Deploy the vendor‑provided patch (version 26.3) immediately.
  • Verify that all endpoints running Avast Premium Security are updated via centralized patch‑management.
  • Enforce strict least‑privilege policies for any code that can execute on user workstations.
  • Conduct a focused audit of endpoint logs for anomalous SYSTEM‑level activity.
  • Re‑evaluate the use of third‑party endpoint protection in high‑risk environments until remediation is confirmed.

Source: Zero Day Initiative Advisory – ZDI‑26‑271

📰 Original Source
http://www.zerodayinitiative.com/advisories/ZDI-26-271/

This LiveThreat Intelligence Brief is an independent analysis. Read the original reporting at the link above.

🛡️

Monitor Your Vendor Risk with LiveThreat™

Get automated breach alerts, security scorecards, and intelligence briefs when your vendors are compromised.