Cryptomator encrypts cloud data through vaults, but from version 1.6.0 to just before 1.19.1 the system parses the vault configuration before checking its integrity. The masterkeyfile loader treats the keyId supplied in the configuration as a file‑system path without validation. An attacker can insert parent‑directory escapes or absolute paths – for example using a masterkeyfile://prefix that resolves to a UNC share – so the application will call the path existence check before any password is entered. This can allow reading of arbitrary local files or triggering outbound SMB requests to attacker controlled shares, potentially exposing sensitive data.

Cryptomator versions 1.6.0 through 1.19.0 on any platform detected by the CPE – particularly Windows, where UNC resolution is risky. The vulnerability does not affect earlier versions or 1.19.1 and later. The affected software is the Cryptomator desktop application distributed by the vendor cryptomator:cryptomator. Windows operating systems are especially relevant because of the SMB path resolution.

The CVSS score of 4.1 reflects moderate risk; the EPSS score shows less than 1% probability of exploitation today, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Exploitation requires a user to load or open a vault whose configuration contains a malicious masterkeyfile keyId, which the attacker can supply via a compromised cloud folder or a phishing attachment. Once the vault is opened, the existence check for the supplied path occurs before the user enters the vault password, so the exploit can succeed without further interaction. Consequently, the main risk is local or network file disclosure rather than remote code execution.