CVE-2026-52885
Notepad++ TOCTOU: HMAC Checks Disk, Executes from Memory
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.
INFO
Published Date :
June 26, 2026, 9:16 p.m.
Last Modified :
June 29, 2026, 9:22 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Notepad++ to version 8.9.6.4.
- Apply vendor patches for Notepad++.
- Ensure shortcuts.xml integrity.
Public PoC/Exploit Available at Github
CVE-2026-52885 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52885.
| URL | Resource |
|---|---|
| https://github.com/notepad-plus-plus/notepad-plus-plus/commit/4f7563c7c7f8ffa0d795ec86a7777067c7d644b5 | Patch |
| https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-qm4c-qg8p-qfcr | Exploit Patch Vendor Advisory |
| https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-qm4c-qg8p-qfcr | Exploit Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52885 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-52885
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.
security cve exploit poc vulnerability
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-52885 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52885 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 29, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:notepad-plus-plus:notepad++:*:*:*:*:*:*:*:* versions up to (excluding) 8.9.6.4 Added Reference Type GitHub, Inc.: https://github.com/notepad-plus-plus/notepad-plus-plus/commit/4f7563c7c7f8ffa0d795ec86a7777067c7d644b5 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-qm4c-qg8p-qfcr Types: Exploit, Patch, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-qm4c-qg8p-qfcr Types: Exploit, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 29, 2026
Action Type Old Value New Value Added Reference https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-qm4c-qg8p-qfcr Added SSVC {'id': 'CVE-2026-52885', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-29T13:11:30.827250Z'} -
New CVE Received by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'notepad-plus-plus', 'product': 'notepad-plus-plus', 'versions': [{'status': 'affected', 'version': '< 8.9.6.4'}]}] Added 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. Added CVSS V4.0 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 Added CWE CWE-367 Added Reference https://github.com/notepad-plus-plus/notepad-plus-plus/commit/4f7563c7c7f8ffa0d795ec86a7777067c7d644b5 Added Reference https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-qm4c-qg8p-qfcr