CVE-2025-56383: CVE-2025-56383: Notepad++ v8.8.3 has a DLL hijacking vulnerability, which can replace the original DLL fil…

What it is

Notepad++ v8.8.3 has a DLL hijacking vulnerability, which can replace the original DLL file to execute malicious code. NOTE: this is disputed by multiple parties because the behavior only occurs when a user installs the product into a directory tree that allows write access by arbitrary unprivileged users.

Exploitation evidence

First exploit evidence seen: 2025-09-26 (earliest date across the sources below).

Exploited in the wild

No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).

Public exploit code

GitHub proof-of-concept repositories

2 public repositories from 2 accounts, first seen 2025-09-26. Most starred: zer0t0/CVE-2025-56383-Proof-of-Concept (57 stars), view repository.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: nomi-sec/PoC-in-GitHub.

How to fix it

Fixed versions

NVD does not list a fixed version for this CVE. Use the vendor advisory below.

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

No vendor-tagged reference yet; see the full reference list.

MITRE ATT&CK mitigations for this chain

• M1038 Execution Prevention (for T1574.001) : Identify and block potentially malicious software executed through DLL hijacking by using application control solutions capable of blocking DLLs loaded by legitimate software.
• M1044 Restrict Library Loading (for T1574.001) : Disallow loading of remote DLLs. This is included by default in Windows Server 2012+ and is available by patch for XP+ and Server 2003+. Enable Safe DLL Search Mode to move the user's current folder later in the search order. This is included by default in modern versions of Windows; the associated Windows Registry ke
• M1051 Update Software (for T1574.001) : Update software regularly to include patches that fix DLL side-loading vulnerabilities.
• M1047 Audit (for T1574.001) : Use auditing tools capable of detecting DLL search order hijacking opportunities on systems within an enterprise and correct them. Toolkits like the PowerSploit framework contain PowerUp modules that can be used to explore systems for DLL hijacking weaknesses. Use the program `sxstrace.exe` that is included with Windo
• M1013 Application Developer Guidance (for T1574.001) : When possible, include hash values in manifest files to help prevent side-loading of malicious libraries.

Detection Generic guidance

• Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.