Notepad++ release 8.9.6.4

[donho]

Notepad++ release 8.9.6.4 is available:

https://notepad-plus-plus.org/news/v8964-released/

Notepad++ v8.9.6.4 vulnerability fix, regression-fix & bug-fix:

1. Fix TOCTOU (Time-of-check to time-of-use) issue in HMAC implementation. (Fix TOCTOU)
2. Fix MSI installer regression that leaves old version entry in Add/Remove Programs. (Fix #18071)
3. Fix “Open Containing Folder in Explorer” launching extra explorer processes. (Fix #17941)

Notepad++ v8.9.6.2 vulnerability fix:

1. Fix a bypass scenario in the previously fixed vulnerability (CVE-2026-48800) that was not fully addressed. (Implement commit)

Notepad++ v8.9.6.1 vulnerability fixes:

1. Fix bad formed COPYDATASTRUCT makes Notepad++ crash (CVE-2026-48770).
2. Fix arbitrary code execution vulnerability via config.xml (CVE-2026-48778).
3. Fix arbitrary code execution vulnerability via shortcuts.xml (CVE-2026-48778).

Notepad++ v8.9.6. regression fixes, bug-fixes:

1. Fix vulnerability (CVE-2026-46710) of v8.9.4 & v8.9.5 installer. (Implement commit)
2. Fix x86 installer regression of not showing installation entry in “Unstall a program” of Control Panel. (Fix community discussion)
3. Fix x86 installer regression where context menu not installed or uninstalled correctly. (Fix community discussion)
4. Fix UAC prompt display regression (“Notepad++ installer” instead of “Notepad++”) for Notepad++ v8.9.5. (Fix GitHub comment)
5. Fix incorrect bevaviour when saving dirty read-only files. (Fix #17956)
6. Fix regression where saving a UDL file removed XML declaration. (Fix GitHub comment)

Notepad++ v8.9.5 regression fixes, bug-fixes & new improvements:

1. Fix updating issue where using v8.9.4 32-bits installer creates duplicate “Uninstall a program” entries. (Fix #17979)
2. Fix v8.9.4 64-bits installer error message caused by MSIX on Win10. (Fix installer regression)
3. Fix regression in UDL xml file EOL parsing issue. (Fix #18022)
4. Update Scintilla to 5.6.2 & Lexilla to 5.4.9. (Implement #18011)
5. Add option to synchronize zoom level across views. (Fix #17862)
6. Fix MSI installer writting language info to HKCU instead of HKLM. (Fix MSI issue)
7. Fix imported UDLs not appearing in the language menu without restarting Notepad++. (Fix #17909)
8. Make “(?)” tooltip in preferences & Find in Files dialogs persitant & reduce display delay. (Fix #17995, #16961)
9. Fix visual glitch in Mark dialog when in reduced mode. (Fix #17983)

Notepad++ v8.9.4 crash-fixexs, bug-fixes & new improvements:

1. Fix crashes in FindInFiles when nativeLang.xml’s “find-result-hits” contains “%s”. (Fix #17960, CVE-2026-3008, CVE-2026-6539)
2. Fix drop-file crash when file path length reaches 259 characters. (Fix #17921)
3. Fix crash caused by undoing column editor bad input in virtual space. (Fix #17915)
4. Fix bad column editor input in reverse-direction column selection on virtual space. (Fix #17915)
5. Update to Scintilla 5.6.1 & Lexilla 5.4.8. (Fix #17920, #17864, #13522, #11746)
6. Fix EOL conversion to Windows format not working (Scintilla update related). (Fix #17920)
7. Fix rendering corruption in .bat files (Lexilla update related). (Fix #17864)
8. Fix quote escaping causing incorrect JSON syntax highlighting (Lexilla update related). (Fix #11746, #13522)
9. Fix MSI installation error due to context menu item registration. (Fix #17918)
10. Fix NSIS installation stalling caused by context menu registration issue. (Fix #17308, #17885)
11. Add NPP_LANG property to install a specific localization file for MSI. (Fix issue reported in comment)
12. Fix MSI installer display random Hexadecimal number as name on UAC. (Fix #17967)
13. Add version info into MSI file property (as value of “Comments”). (Fix #17803)
14. Fix minimized window not restoring in administrator mode. (Fix #17945)
15. Fix Unicode search mismatching ANSI character ‘?’. (Fix #17125)
16. Fix Column Editor regression with empty fields. (Fix #17912)
17. Fix floating dialog content not displaying in certain situations. (Fix #17563)
18. Fix visual glitch when toggling group view in Document List. (Fix #14285)
19. Support improved C++ 11 raw string literal handling. (Fix #17875)
20. Fix visual glitch in the Mark dialog. (Fix #16084, #17886)

Auto-updater will be triggered in few days if no issues found.

[MarkusBodensee]

In contrast to the many critical voices (which may well start up again any moment now), I would like to say thank you—for preserving memory and for standing up against ignorance. Nothing is apolitical—neither music nor software—and it is important to stand up for what is right. This holds true not only for this particular event; unfortunately, both in the past and in the present day, there have been far too many such inhumane events.

[PeterJones]

@donho said:

Auto-updater will be triggered in few days if no issues found.

It’s been a few days, with no public regressions that I’ve seen. Does that mean that auto-update will be triggered soon?

[Pull_it_all]

@donho small typo on the website: censored by Microsoft’s search engin Bing on June 4, 2021

[j-haley_otto]

@donho
Hi, I am trying to submit this as an issue on Github, however, I keep receiving an “Error
Unable to create issue.” with no further information, all the while Github appears to be working & I cannot resolve how to submit this issue ticket without any further errors…

Title:
Regression in v8.9.6.4: Open File no longer resolves selected relative paths from current document directory

Body:
Description

In Notepad++ v8.9.6.4, Edit > On Selection > Open File no longer opens selected relative file paths that worked in v8.9.5.

This appears to be a regression in how Open File resolves selected relative paths against the current document directory.

Working version

Notepad++ v8.9.5 64-bit
Build time: May 10 2026 - 22:41:06

Broken version

Notepad++ v8.9.6.4 64-bit
Build time: Jun 3 2026 - 23:47:49

Example file structure

C:\repo\example-repo\Bulk_Master_All.bdf
C:\repo\example-repo\Case_Control\Example_Include_File.bdf

Steps to reproduce

1. Open this file in Notepad++:

C:\repo\example-repo\Bulk_Master_All.bdf

2. Select this relative path text:

…\Case_Control\Example_Include_File.bdf

3. Run Edit > On Selection > Open File, or right-click the selected path and choose Open File.

Expected behavior

Notepad++ should resolve the selected path relative to the current document directory:

C:\repo\example-repo\Bulk…\Case_Control\Example_Include_File.bdf

This normalizes to:

C:\repo\example-repo\Case_Control\Example_Include_File.bdf

The file should open.

Actual behavior

Notepad++ v8.9.6.4 shows:

The path you’re trying to open doesn’t exist

Additional confirmation

Selecting and opening the absolute path works:

C:\repo\example-repo\Case_Control\Example_Include_File.bdf

The expected behavior happens successfully after rolling back to Notepad++ v8.9.5; this has been the case for numerous versions of Notepad++ & never had an issue until now.

This suggests the file exists, permissions are not the problem, and the regression is specific to selected relative path resolution in Open File.

Debug info from broken version

Notepad++ v8.9.6.4 64-bit
Build time: Jun 3 2026 - 23:47:49
Path: C:\Program Files\Notepad++\notepad++.exe
Admin mode: OFF
Local Conf mode: OFF
Cloud Config: OFF
WinGUp: present
disableNppAutoUpdate.xml: absent

Plugins:
ComparePlugin 2.0.2
Explorer 1.9.9
mimeTools 3.1
NppConverter 4.7
NppExport 0.4