Notepad2: Untrusted Search Path
CVE-2026-2538 is a high-severity untrusted search path vulnerability in Notepad2 from Flos Freeware, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Notepad2 versions: 4.2.22; 4.2.23; 4.2.24, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Notepad2 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Flos Freeware | Notepad2 | 4.2.22; 4.2.23; 4.2.24; 4.2.25 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vuldb.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.3 | High | CNA (vuldb.com) |
| CVSS 3.1 | 7.0 | High | CNA (vuldb.com) |
| CVSS 2.0 | 6.0 | Medium | CNA (vuldb.com) |
Official description
A security flaw has been discovered in Flos Freeware Notepad2 4.2.22/4.2.23/4.2.24/4.2.25. Affected is an unknown function in the library Msimg32.dll. Performing a manipulation results in uncontrolled search path. Attacking locally is a requirement. The attack's complexity is rated as high. The exploitability is told to be difficult. The vendor was contacted early about this disclosure but did not respond in any way.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Untrusted Search Path
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control.
How developers prevent this class of flaw
- Hard-code the search path to a set of known-safe values (such as system directories), or only allow them to be specified by the administrator in a configuration file. Do not allow these settings to be modified by an external party. Be careful to avoid related weaknesses such as CWE-426 and CWE-428.
- When invoking other programs, specify those programs using fully-qualified pathnames. While this is an effective approach, code that uses fully-qualified pathnames might not be portable to other systems that do not use the same pathnames. The portability can be improved by locating the full-qualified paths in a centralized, easily-modifiable location within the source code, and having the code refer to these paths.
- Remove or restrict all environment settings before invoking other programs. This includes the PATH environment variable, LD_LIBRARY_PATH, and other settings that identify the location of code libraries, and any application-specific search paths.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Notepad2
- 7.0 High severity
- 7.0 High severity
Recent Untrusted Search Path vulnerabilities
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 9.3 Critical severity
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