CVE-2026-1007: Devolutions Server Auth Bypass Vulnerability

CVE-2026-1007 Overview

CVE-2026-1007 is an Incorrect Authorization vulnerability in the virtual gateway component of Devolutions Server that allows attackers to bypass deny IP rules. This authorization bypass weakness (CWE-863) enables threat actors to circumvent network access controls that administrators have configured to restrict connections from specific IP addresses.

Critical Impact

Attackers can bypass IP-based access controls in Devolutions Server's virtual gateway component, potentially gaining unauthorized access to sensitive resources that should be protected by deny rules.

Affected Products

• Devolutions Server versions 2025.3.1 through 2025.3.12

Discovery Timeline

• 2026-01-19 - CVE CVE-2026-1007 published to NVD
• 2026-01-20 - Last updated in NVD database

Technical Details for CVE-2026-1007

Vulnerability Analysis

This vulnerability stems from an Incorrect Authorization flaw (CWE-863) in how the virtual gateway component processes and enforces IP deny rules. When administrators configure IP-based access restrictions to block connections from specific addresses or ranges, the authorization logic fails to properly validate incoming requests against these rules.

The virtual gateway component is responsible for managing remote connections and enforcing access policies within Devolutions Server. The flawed authorization mechanism allows network-based attackers with high privileges to craft requests that evade the IP deny list enforcement, effectively rendering these security controls ineffective.

The scope of this vulnerability extends beyond the vulnerable component itself, potentially affecting other systems and resources that rely on these IP-based access controls for protection.

Root Cause

The root cause is an Incorrect Authorization vulnerability (CWE-863) in the virtual gateway component's request processing logic. The component fails to properly authorize or validate incoming connection requests against configured deny IP rules before granting access. This authorization bypass occurs due to improper implementation of the access control checks within the virtual gateway's connection handling code.

Attack Vector

The attack is network-based and requires high privileges to exploit. An attacker with elevated access to the system can bypass IP deny rules configured in the virtual gateway component. While user interaction is not required, the attacker must already possess privileged access to the Devolutions Server environment.

The exploitation flow involves:

1. Attacker identifies a Devolutions Server instance running a vulnerable version (2025.3.1 through 2025.3.12)
2. Attacker leverages their high-privilege access to interact with the virtual gateway component
3. Requests are crafted to circumvent the IP deny rule validation logic
4. The virtual gateway incorrectly authorizes the connection despite the attacker's IP being on the deny list
5. Attacker gains access to protected resources or systems

For technical details on the vulnerability mechanism, refer to the Devolutions Security Advisory DEVO-2026-0003.

Detection Methods for CVE-2026-1007

Indicators of Compromise

• Unexpected successful connections from IP addresses that should be blocked by deny rules
• Authentication or access logs showing connections from previously denied IP ranges
• Anomalous virtual gateway activity patterns indicating authorization bypass attempts

Detection Strategies

• Monitor virtual gateway logs for connections originating from IP addresses configured in deny lists
• Implement network traffic analysis to detect access attempts from blocked IP ranges that succeed unexpectedly
• Review Devolutions Server audit logs for privilege escalation or unauthorized resource access patterns

Monitoring Recommendations

• Enable verbose logging on the virtual gateway component to capture detailed connection authorization events
• Configure SIEM alerts for successful connections from IP addresses matching deny rule patterns
• Regularly audit IP deny rule configurations against actual connection logs to identify potential bypasses

How to Mitigate CVE-2026-1007

Immediate Actions Required

• Upgrade Devolutions Server to a version beyond 2025.3.12 that contains the security fix
• Review and audit all IP deny rules configured in the virtual gateway component
• Implement additional network-level access controls (firewalls, network ACLs) as defense-in-depth measures
• Monitor virtual gateway logs for any signs of unauthorized access from blocked IP addresses

Patch Information

Devolutions has released a security advisory addressing this vulnerability. Organizations should upgrade to the latest patched version of Devolutions Server. For specific patch details and download information, consult the Devolutions Security Advisory DEVO-2026-0003.

Workarounds

• Implement network-level firewall rules to enforce IP restrictions as an additional layer of defense
• Restrict access to the virtual gateway component to only trusted networks and users with verified business needs
• Consider temporarily disabling the virtual gateway component if it is not critical to operations until patching is complete
• Enable enhanced logging and monitoring on all virtual gateway connections to detect potential bypass attempts