- Exploited
- No known exploitation
- Fix
- Fixed in 26.7
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 26.7.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 0/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The AvastSvc service on Windows can be crashed by a local, unprivileged user who sends specially crafted JSON messages to its native message handlers, causing denial of service. The crash happens because JSON type conversions in several handlers have no exception handling, so errors propagate up and take down the service.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original 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.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity?/10Unknown. No CVSS score or vendor rating
- No patch0/5No signal
What would change the score
- Would score about 55 if added to CISA KEV
- Would score about 50 if CISA's SSVC rates exploitation active
- Would score about 22 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 26.7.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- Gen Digital Avast Antivirus, Avast One, Avast Premium Security, Avast Ultimate, Avast Business Security
fixed in 26.7
- Gen Digital AVG Antivirus Free, AVG Internet Security, AVG Ultimate
fixed in 26.7
- Gen Digital Norton Antivirus Plus, Norton 360 Standard, Norton 360 Deluxe, Norton 360 Advanced
fixed in 26.7
Evidence 4
- Advisory
- Patch
- Patch
- Patch
Corrections
None so far.
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Questions about CVE-2026-12067
Is CVE-2026-12067 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-12067?
Avast Antivirus, Avast One, Avast Premium Security, Avast Ultimate, Avast Business Security: before 26.7. AVG Antivirus Free, AVG Internet Security, AVG Ultimate: before 26.7. Norton Antivirus Plus, Norton 360 Standard, Norton 360 Deluxe, Norton 360 Advanced: before 26.7.Source: cve.now feed data
How do I fix CVE-2026-12067?
Upgrade to a fixed version: 26.7.Source: cve.now feed data