Out-of-bounds Read in Notepad-plus-plus Notepad\+\+

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 appea…

Vulnerability class: Buffer Overflow

EPSS: 0.003 (17.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-48770?
CVE-2026-48770 is a medium-severity vulnerability in Notepad-plus-plus Notepad\+\+, classified under Out-of-bounds Read. CVSS score: 5.0/10. Published 2026-06-26.
How severe is CVE-2026-48770?
Medium severity. CVSS v3 base score is 5.0 out of 10.
Is CVE-2026-48770 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.