Code execution via out-of-bounds regex compilation
Published Mar 24, 2026 · Updated Mar 24, 2026
Out-of-bounds read in Notepad3 before 6.25.714.1 allows context-dependent attackers to execute code via a crafted regex pattern. The bundled Oniguruma compile_string_node() routine trusts an encoded character length without clamping it to the regex buffer end, so a truncated final character drives a heap read past the allocation. Exploitation requires a victim to trigger compilation of the crafted pattern in the local Windows application, after which attacker-controlled code runs in that user context.
Summary
What happened
Out-of-bounds read in Notepad3 before 6.25.714.1 allows context-dependent attackers to execute code via a crafted regex pattern. The bundled Oniguruma compile_string_node() routine trusts an encoded character length without clamping it to the regex buffer end, so a truncated final character drives a heap read past the allocation. Exploitation requires a victim to trigger compilation of the crafted pattern in the local Windows application, after which attacker-controlled code runs in that user context.
The record
- CVE
- CVE-2026-4744
- Published
- Mar 24, 2026
- Updated
- Mar 24, 2026
- Vendor
- Rizonesoft
- Product
- Notepad3
- Classifications
- CWE-125, T1204
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 24, 2026CVE publishedPublication date reported by the CVE source.
- Mar 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.25.714.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo