ZeroDay Findings
Sign inSign up

Findings

CVE-2025-15556

Notepad++ Download of Code Without Integrity Check Vulnerability

Published Feb 2, 2026 · updated Jun 17, 2026 · Notepad++ Notepad++

Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity verification vulnerability where downloaded update metadata and installers are not cryptographically verified. An attacker able to intercept or redirect update traffic can cause the updater to download and execute an attacker-controlled installer, resulting in arbitrary code execution with the privileges of the user.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 2, 2026 · Catalog

    Detected

    Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity verification vulnerability where downloaded update metadata and installers are not cryptographically verified. An attacker able to intercept or redirect update traffic can cause the updater to download and execute an attacker-controlled installer, resulting in arbitrary code execution with the privileges

  2. Feb 12, 2026 · CISA KEV

    Known exploited

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  3. Mar 5, 2026 · CISA KEV

    Remediation due

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  4. Jun 17, 2026 · Catalog

    Updated

    Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity verification vulnerability where downloaded update metadata and installers are not cryptographically verified. An attacker able to intercept or redirect update traffic can cause the updater to download and execute an attacker-controlled installer, resulting in arbitrary code execution with the privileges

Required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

CISA due date Mar 5, 2026

Affected

  • cpe notepad-plus-plus/notepad++version unspecified
  • vendor Notepad++ Notepad++version unspecified

Sources

  • CISA KEVCVE-2025-15556

    Notepad++ when using the WinGUp updater, contains a download of code without integrity check vulnerability that could allow an attacker to intercept or redirect update traffic to download and execute an attacker-controlled installer. This could lead to arbitrary code execution with the privileges of the user.

    cisa.gov
  • CVE.orgCVE-2025-15556

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2025-15556

    30-day exploitation probability 1.8%

    first.org
  • NIST NVDCVE-2025-15556

    Notepad++ versions prior to 8.8.9, when using the WinGUp updater, contain an update integrity verification vulnerability where downloaded update metadata and installers are not cryptographically verified. An attacker able to intercept or redirect update traffic can cause the upda

    nvd.nist.gov

References