Vulnerability Intelligence Report
Notepad++ WM_COPYDATA COPYDATA_FULL_CMDLINE local DoS crash
CVE-2026-48770
Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, a local process in the same interactive Windows session can send a malformed WM_COPYDATA message to Notepad++ using the COPYDATA_FULL_CMDLINE path. The handler appears to process COPYDATASTRUCT.lpData as an unbounded NUL-terminated wchar_t* instead of enforcing COPYDATASTRUCT.cbData. This vulnerability is fixed in 8.9.6.1.
No Active Exploit Signals
CVSS Base Score
5.0
MEDIUM
Exploitability:1.4
Impact Score:3.6
EPSS Probability:0.27%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-125 ↗CWE-125: Out-of-bounds Read
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| notepad-plus-plus | notepad-plus-plus | < 8.9.6.1 (affected) |
Threat Intelligence Signals
EPSS Score
0.270%
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | GitHub, Inc. · Vendor · USA |
| Reserved | 2026-05-22T19:39:05 |
| Published | 2026-06-26T20:22:17 |
| Last Updated | 2026-06-29T12:11:59 |
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