Vulnerability in Gen Digital Avast Antivirus, One, Premium Security, Ultimate, Business Security

CVE-2026-12067

Missing exception handlers in AvastSvc native message dispatcher (ashServ.dll) on Windows allow a local, unprivileged attacker to crash the service by sending specially crafted JSON messages. The vulnerability spans multiple handler pathways in the RPC-based native message protocol: * Log_NmSvc.message handler: converts JSON fields to strings without type validation and without exception boundaries.  * OpenInSz_NmSvc handler: converts URL and origin fields to strings without type checking, exposing an exception. * OpenInSz_NmSvc.profile handler: converts the profile field to an integer without validation. In all three cases, the exceptions are not caught by action-specific handlers and propagate up the dispatcher. The common root cause is the absence of try-catch blocks around JSON type conversions in the native message processing chain.

Published .

EPSS exploit prediction

EPSS: 0.002 (4.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 4.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

References