CVE-2026-48770: Notepad++ is a free and open-source source code editor

Q: How do I fix CVE-2026-48770?

notepad\+\+: upgrade to 8.9.6.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-48770 being exploited?

CVE-2026-48770 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-48770 affect?

CVE-2026-48770 affects notepad\+\+. Severity is medium (CVSS 5.0). Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, a local process in the same interactive Windows session can send a malformed WM_COPYDATA message to Notepad++ using the COPYDATA_FULL_CMDLINE path. The handler appear

Q: How urgent is CVE-2026-48770?

Priority 23/100. Public exploit reference

Routine

MEDIUM 5.0UPGRADE

CVE-2026-48770 is a medium-severity flaw (CVSS 5.0) affecting notepad\+\+. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, a local process in the same interactive Windows session can send a malformed WM_COPYDATA message to Notepad++ using the COPYDATA_FULL_CMDLINE path. The handler appears to process COPYDATASTRUCT.lpData as an unbounded NUL-terminated wchar_t* instead of enforcing COPYDATASTRUCT.cbData. This vulnerability is fixed in 8.9.6.1.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.1% (top 97%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-06-26
Last modified	2026-06-29

Publisher (CNA): GitHub, Inc. · Vendor: notepad-plus-plus

Last updated 2026-06-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-26 21:16 UTCPublished CVE record published
2026-06-29 21:21 UTCUpdated Record last modified

notepad-plus-plus notepad\+\+ UPGRADE

Affected: < 8.9.6.1

Fixed in: 8.9.6.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy notepad++ || rpm -q notepad++ || notepad++ --version

2. UPGRADE to 8.9.6.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade notepad++

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade notepad++

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48770?

notepad\+\+: upgrade to 8.9.6.1. Exact commands for each OS are on this page.

Is CVE-2026-48770 being exploited?

CVE-2026-48770 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48770 affect?

CVE-2026-48770 affects notepad\+\+. Severity is medium (CVSS 5.0). Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, a local process in the same interactive Windows session can send a malformed WM_COPYDATA message to Notepad++ using the COPYDATA_FULL_CMDLINE path. The handler appear

How urgent is CVE-2026-48770?

Priority 23/100. Public exploit reference

Software pages

Windows vulnerabilities · Notepad++ vulnerabilities

Related CVEs

CVE-2026-5525 MEDIUM 6.0 DOWNGRADE A stack-based buffer overflow vulnerability exists in Notepad++ version 8.9.3 in the file drop handler compone
CVE-2026-48800 HIGH 7.8 UPGRADE Notepad++ is a free and open-source source code editor
CVE-2026-52885 MEDIUM 6.3 UPGRADE Notepad++ is a free and open-source source code editor
CVE-2026-52884 HIGH 7.8 DOWNGRADE Notepad++ is a free and open-source source code editor
CVE-2026-48778 HIGH 7.8 UPGRADE Notepad++ is a free and open-source source code editor

References

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