What is CVE-2026-48778?
Notepad++ (versions up to and including v8.9.6) fails to validate the commandLineInterpreter setting stored in its config.xml configuration file. The value of the tag is read and stored without any validation, allow-list, or digital-signature check. When a user triggers the "File -> Open Containing Folder -> cmd" action, Notepad++ passes the attacker-controlled string directly to ShellExecute(), executing whatever interpreter/executable the attacker specified. An attacker who can modify config.xml -- for example via direct file-system access to the user's AppData directory, malicious shortcuts using the -settingsDir parameter, cloud-sync poisoning, or tricking the user into extracting a crafted archive -- can therefore achieve arbitrary code execution. A proof-of-concept replacing the tag value with calc.exe causes Windows Calculator to launch in place of the command prompt, confirming code execution. The issue was fixed in Notepad++ v8.9.6.1.
The record classifies CVE-2026-48778 under weakness class CWE-78. Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 125 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.8 — HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 0.6% probability of exploitation in the next 30 days, higher than 48.1% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 7.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-06-26, last modified 2026-06-29
Is CVE-2026-48778 being exploited?
Weaponised exploit code for CVE-2026-48778 is publicly available. 3 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 29 in the Threadlinqs vulnerability feed.
- XK3NF4/CVE-2026-48778 (github)
- kavin-jindal/CVE-2026-48778-PoC (github)
- trickest/cve (trickest)
Affected products and versions
- notepad-plus-plus: notepad-plus-plus
How to fix CVE-2026-48778
No vendor patch reference has been recorded for CVE-2026-48778 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-48778
1 tracked threat in the Threadlinqs corpus references CVE-2026-48778, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on .