Zip Slip in SonicWall NSM Allows Directory Traversal via File Upload
CVE-2026-81939 Published on September 4, 2026

A Zip Slip vulnerability in the SonicWall Network Security Manager (NSM) On-Prem file upload and archive processing functionality allows an attacker to extract files outside the intended destination directory using a specially crafted archive.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-81939 can be exploited with network access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
HIGH
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Directory traversal Vulnerability?

The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVE-2026-81939 has been classified to as a Directory traversal vulnerability or weakness.


Affected Versions

SonicWall Network Security Manager (NSM) Version 4.3.0 and earlier versions is affected by CVE-2026-81939