Local code execution via PROPSYS.dll search hijacking
Published Mar 22, 2026 · Updated Mar 22, 2026
DLL search-order hijacking in flo's freeware Notepad2 4.2.25 allows local users to execute code through a crafted PROPSYS.dll. The application loads PROPSYS.dll from its executable directory without restricting the search to a trusted system location, selecting an attacker-placed library before the legitimate copy. Exploitation requires low-privileged local access to place the DLL beside notepad2.exe and run the application; the demonstrated payload opens a reverse shell with the application's privileges.
Summary
What happened
DLL search-order hijacking in flo's freeware Notepad2 4.2.25 allows local users to execute code through a crafted PROPSYS.dll. The application loads PROPSYS.dll from its executable directory without restricting the search to a trusted system location, selecting an attacker-placed library before the legitimate copy. Exploitation requires low-privileged local access to place the DLL beside notepad2.exe and run the application; the demonstrated payload opens a reverse shell with the application's privileges.
The record
- CVE
- CVE-2026-4545
- Published
- Mar 22, 2026
- Updated
- Mar 22, 2026
- Vendor
- flo's freeware
- Product
- Notepad2
- Classifications
- CWE-426, CWE-427, T1574.001
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 22, 2026CVE publishedPublication date reported by the CVE source.
- Mar 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.2.25
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- PROPSYS.dll reverse-shell demonstrationfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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