CVE-2026-86054 Notepad++ - Buffer Overflow

Notepad++ < 8.9.8 contains a stack buffer overflow caused by unbounded wcscpy and wcscat operations in NppParameters::writeSession, letting attackers cause denial of service by triggering stack canary termination, exploit requires a long settings directory path.

CVSS base score 7.8 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.23% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Buffer Overflow
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
22 September 2026
Updated
15 October 2026
Weakness
CWE-121

Vendor fix

Update to version 8.9.8 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

← All CVEs