Is CVE-2026-48770 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-48770 being exploited in the wild.

How severe is CVE-2026-48770?

Medium severity, with a CVSS score of 5, published 26 June 2026.

Is there a fix for CVE-2026-48770?

A patch was published on 2026-06-26: Fix included in version 8.9.6.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-48770 attacked?

It is attacked with local access, in a network appliance.

Am I affected by CVE-2026-48770?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-48770: Notepad++ out-of-bounds read in WM_COPYDATA handler

CVE-2026-48770 · Severity: medium · CVSS 5 · Published 2026-06-26

Notepad++ is a popular open-source text and source code editor for Windows. A vulnerability in how the application handles internal communication messages allows other programs running on the same computer to force Notepad++ to crash. This results in a denial-of-service where a user may lose unsaved work if a malicious or malfunctioning local process triggers the flaw.

Quick answers

Is CVE-2026-48770 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-48770 being exploited in the wild.
How severe is CVE-2026-48770?: Medium severity, with a CVSS score of 5, published 26 June 2026.
Which products and versions are affected?: Notepad++ Notepad++ < 8.9.6.1.
Is there a fix for CVE-2026-48770?: A patch was published on 2026-06-26: Fix included in version 8.9.6.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48770 attacked?: It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-48770?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An out-of-bounds read vulnerability (CWE-125) exists in Notepad++ prior to version 8.9.6.1. The issue resides in the handling of 'WM_COPYDATA' messages, specifically within the 'COPYDATA_FULL_CMDLINE' path in 'NppBigSwitch.cpp'. The application processes 'COPYDATASTRUCT.lpData' as an unbounded, NUL-terminated 'wchar_t*' string without validating the 'cbData' length field. By sending a malformed message with a large 'cbData' value and a buffer lacking a NUL terminator, a local process in the same interactive session can trigger an access violation (0xc0000005). This results in a reliable application crash. The vulnerability is fixed in version 8.9.6.1 by implementing proper bounds checking and exception handling during command-line string processing.

Affected products

Notepad++ Notepad++ < 8.9.6.1

Timeline

2026-05-26: advisory: GitHub Security Advisory published by vendor
2026-06-26: disclosed: CVE published to NVD
2026-06-26: patched: Fix included in version 8.9.6.1

References

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