Notepad++ TOCTOU: HMAC Checks Disk, Executes from Memory
Summary
| CVE | CVE-2026-52885 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-26 21:16:34 UTC |
| Updated | 2026-06-29 21:22:34 UTC |
| Description | Notepad++ is a free and open-source source code editor. Prior to 8.9.6.4, NppCommands.cpp checks the HMAC of the on-disk shortcuts.xml at the moment a user command fires (Time-of-Check). However, the command payload is taken from the in-memory _userCommands vector, which is populated at application startup and never re-synchronized with the on-disk file (Time-of-Use). Swapping shortcuts.xml between startup and command execution causes the HMAC check to validate a clean file while a malicious command runs. An attacker with write access to shortcuts.xml places a malicious version on disk before launch, then immediately restores the legitimate file. The HMAC check at execution time validates the restored legitimate file (check passes), while the malicious payload executes from memory. This vulnerability is fixed in 8.9.6.4. |
Risk And Classification
Primary CVSS: v4.0 7.5 HIGH from [email protected]
CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.001290000 probability, percentile 0.029220000 (date 2026-06-30)
Problem Types: CWE-367 | CWE-367 CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7.5 | HIGH | CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | DECLARED | 7.5 | HIGH | CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 6.3 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
HighAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
HighPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Notepad-plus-plus | Notepad | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Notepad-plus-plus | Notepad-plus-plus | affected < 8.9.6.4 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | Exploit, Patch, Vendor Advisory |
| github.com/notepad-plus-plus/notepad-plus-plus/commit/4f7563c7c7f8ffa0d7... | [email protected] | github.com | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.