CVE-2026-48770

Notepad++ WM_COPYDATA COPYDATA_FULL_CMDLINE local DoS crash

MEDIUM
5
CVSS Score
Published: June 26, 2026 at 08:22 PM UTC
Updated: July 1, 2026 at 11:22 PM UTC
2 products affected across 1 vendorNotepad++Plus Plus Notepad

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Severity
MEDIUM5
Exploit prediction
EPSS 0.1%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 8.9.6.1
Affected range stops below 8.9.6.1, so it looks safe — our inference, not a vendor statement
v < 8.9.6.1
Affected range stops below 8.9.6.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5MEDIUMGitHub_M
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

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