Cryptomator 1.19.1 CheckHostTrustController Logic Flaw Bypass HTTPS/80 Authority
CVE-2026-33472 Published on April 16, 2026
Cryptomator Hub OAuth token exchange HTTP downgrade via getAuthority() scheme confusion (CVE-2026-32303 bypass)
Cryptomator is an open-source client-side encryption application for cloud storage. Version 1.19.1 contains a logic flaw in CheckHostTrustController.getAuthority() that allows an attacker to bypass the security fix for CVE-2026-32303. The method hardcodes the URI scheme based on port number, causing HTTPS URLs with port 80 to produce the same authority string as HTTP URLs, which defeats both the consistency check and the HTTP block validation. An attacker with write access to a cloud-synced vault.cryptomator file can craft a Hub configuration where apiBaseUrl and authEndpoint use HTTPS with port 80 to pass auto-trust validation, while tokenEndpoint uses plaintext HTTP. The vault is auto-trusted without user prompt, and a network-positioned attacker can intercept the OAuth token exchange to access the Cryptomator Hub API as the victim. This issue has been fixed in version 1.19.2.
Vulnerability Analysis
CVE-2026-33472 is exploitable with network access, requires user interaction and a small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. Public availability of a proof of concept (POC) exploit exists for CVE-2026-33472. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Weakness Types
Authentication Bypass by Primary Weakness
The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.
Cleartext Transmission of Sensitive Information
The software transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors. Many communication channels can be "sniffed" by attackers during data transmission. For example, network traffic can often be sniffed by any attacker who has access to a network interface. This significantly lowers the difficulty of exploitation by attackers.