Medium severity · published Jun 26, 2026
CVE-2026-48770
Notepad++ WM_COPYDATA COPYDATA_FULL_CMDLINE local DoS crash
5.0
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NO
notepad-plus-plus · notepad-plus-plus
< 8.9.6.1 · source: vendor
NO
Notepad++ · Notepad-plus-plus
before 8.9.6.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-48770
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-48770
Patch
https://github.com/notepad-plus-plus/notepad-plus-plus/commit/f20a0888a92ce557a339b833cd9d9d8e97dc797d
Exploit
https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-r39g-3mcw-xcg2
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