Chaotic Eclipse Claims Avast Antivirus 0-Day Vulnerability

Cybersecuritynews •Abinaya • September 3, 2026

Researcher Chaotic Eclipse has claimed to have discovered a zero-day privilege-escalation vulnerability affecting Avast Antivirus and released a public proof-of-concept repository named PrettyPrague. The researcher behind the project, using the GitHub handle MSNightmare, says the issue can be exploited on fully patched Avast Antivirus installations running fully updated Windows 11 25H2 systems. The alleged flaw […]

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Zero-Day Exploit Discovered in Avast Antivirus A proof-of-concept exploit named PrettyPrague has been released for a privilege escalation vulnerability in Avast Antivirus, allowing attackers to dump the Windows Security Account Manager (SAM) database and execute commands as NT AUTHORITY\SYSTEM. The exploit affects all versions of Avast Antivirus and potentially other Gen Digital products, including AVG and Norton. The researcher, known as Chaotic Eclipse or MSNightmare, published the exploit on August 30, 2026, and it quickly gained traction on GitHub, reaching 125 stars and 31 forks within 24 hours. Gen Digital has not publicly acknowledged the vulnerability or provided any patches or workarounds. Security professionals are advised to monitor for unusual activity related to the SAM registry hive and rotate local account credentials as a precaution. 6 sources 68

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Chaotic Eclipse Claims Avast Antivirus 0-Day Vulnerability

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