CVE-2026-12067
AvastSvc denial of service via unhandled JsonCpp exceptions in native message handlers
Description
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.
INFO
Published Date :
Nov. 6, 2026, 4:17 p.m.
Last Modified :
Nov. 6, 2026, 4:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-12067
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Add try-catch blocks around JSON type conversions.
- Validate all JSON fields before conversion.
- Ensure exceptions are handled gracefully.
- Apply vendor patches when available.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-12067.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-12067 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-12067
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-12067 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-12067 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Nov. 06, 2026
Action Type Old Value New Value Added Description 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. Added CWE CWE-248 Added CWE CWE-391 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/12xxx/CVE-2026-12067.json">CVE-2026-12067</a> Added Reference https://support.avast.com/en-us/article/Update-Antivirus Added Reference https://support.avg.com/SupportArticleView?l=en&urlname=Update-AVG-Antivirus Added Reference https://support.norton.com/sp/en/us/home/current/solutions/v20240108175512167 Added Reference https://www.gendigital.com/us/en/contact-us/security-advisories/