# CVE-2026-48770

> As of 2026-09-13, CVE-2026-48770 is a MEDIUM-severity vulnerability, CVSS v3.1 5, EPSS 0.0% (1.7th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-48770, most recently “Notepad++ v8.9.6 — Critical Arbitrary Code Execution via config.xml commandLineInterpreter and shortcuts.xml (CVE-2026-48770, CVE-2026-48778, CVE-2026-48800)”.

**Last updated:** 2026-09-13

## What is CVE-2026-48770?

A local denial-of-service vulnerability in Notepad++ (versions <= v8.9.6) caused by improper handling of an inter-process WM_COPYDATA message on the COPYDATA_FULL_CMDLINE path. A local process running in the same interactive Windows session can send a malformed WM_COPYDATA message; the handler processes the data as an unbounded NUL-terminated string rather than respecting the declared buffer size (COPYDATASTRUCT.cbData), triggering an out-of-bounds read / crash that reliably causes a local denial of service against notepad++.exe. Fixed in v8.9.6.1. Disclosed by Enrique de Clerck, Leonardo Gutierrez, and Daniel Cifuentes. NOTE: CVE-2026-48770 is a local DoS crash (CWE-125); the arbitrary-code-execution / config.xml commandLineInterpreter issue is a separate CVE (CVE-2026-48778) patched in the same v8.9.6.1 release.

The record classifies CVE-2026-48770 under weakness class [CWE-125](https://cwe.mitre.org/data/definitions/125.html). Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs a user to take an action first, and has high impact on availability.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 5 — MEDIUM (`CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.0% probability of exploitation in the next 30 days, higher than 1.7% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 2.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability

## Is CVE-2026-48770 being exploited?

It currently carries a trending score of 5 in the Threadlinqs vulnerability feed.

## Affected products and versions

No affected-product or package list has been recorded for CVE-2026-48770 in the tracked sources. The vendor advisory and the references below are the authoritative statement of what is affected.

## How to fix CVE-2026-48770

No vendor patch reference has been recorded for CVE-2026-48770 in the tracked sources. Follow the references below for a fix, and treat any affected deployment as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-48770

1 tracked threat in the Threadlinqs corpus references CVE-2026-48770, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Notepad++ v8.9.6 — Critical Arbitrary Code Execution via config.xml commandLineInterpreter and shortcuts.xml (CVE-2026-48770, CVE-2026-48778, CVE-2026-48800)](https://intel.threadlinqs.com/threat/TL-2026-0613) — CRITICAL · 2026-05-28

## Sources

Seeded from `research_verified` and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

- [github.com](https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-r39g-3mcw-xcg2)
- [heise.de](https://www.heise.de/en/news/Notepad-Gaps-allow-injection-of-malware-and-commands-11309228.html)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-48770
Full detection coverage and IOCs for threats exploiting CVE-2026-48770 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp