CVE-2026-45221: Konga Privilege Escalation Vulnerability

CVE-2026-45221 Overview

Konga versions prior to 2.1.0 contain a privilege escalation vulnerability rooted in insecure library loading behavior [CWE-427]. The application references a hardcoded OpenSSL configuration and library path that does not exist on default installations. On Windows systems, the missing parent directory sits in a location writable by any authenticated local user. A low-privileged attacker can create the directory, plant malicious openssl.cnf or DLL files, and wait for Konga to load them. The planted code executes with the privileges of the user or service account that runs Konga, enabling local privilege escalation.

Critical Impact

Authenticated local users on Windows hosts can escalate privileges to the account running Konga, including service accounts with elevated rights.

Affected Products

• Konga versions prior to 2.1.0
• Windows installations of Konga where the hardcoded OpenSSL path is writable by authenticated users
• Deployments where Konga runs under a privileged user or service account

Discovery Timeline

• 2026-09-01 - CVE-2026-45221 published to NVD
• 2026-09-02 - Last updated in NVD database

Technical Details for CVE-2026-45221

Vulnerability Analysis

The vulnerability stems from Konga referencing a hardcoded filesystem path for OpenSSL configuration and library files. The path does not exist in default installations. On Windows, the parent directory of the missing path resides in a location where any authenticated local user can create files and folders. This condition falls under CWE-427: Uncontrolled Search Path Element.

When Konga initializes cryptographic routines, it attempts to load configuration data such as openssl.cnf and supporting library components from the hardcoded location. Because the directory is absent, an attacker can preemptively create it and stage malicious content. OpenSSL configuration files support directives that can load arbitrary shared libraries at process startup, giving attackers a reliable code execution primitive inside the Konga process.

Root Cause

The root cause is the use of a hardcoded, world-writable filesystem path for security-sensitive resources. The application does not validate the ownership or integrity of the OpenSSL configuration and library files it loads. Absent directories in user-writable locations create a claim-and-plant opportunity for local attackers.

Attack Vector

Exploitation requires local access with low privileges. An attacker creates the missing directory in the hardcoded path and places a crafted openssl.cnf file that references a malicious DLL. The next time Konga starts, or when a privileged user or service invokes it, the OpenSSL loader parses the attacker-controlled configuration and executes the referenced code in the context of that process. Refer to the VulnCheck Advisory: Konga Privilege Escalation for the exact path details.

Detection Methods for CVE-2026-45221

Indicators of Compromise

• Creation of the hardcoded OpenSSL directory on Windows hosts by non-administrative users
• Presence of openssl.cnf or unsigned DLL files inside the hardcoded OpenSSL path on systems running Konga
• Konga process loading DLLs from user-writable directories outside its install path

Detection Strategies

• Monitor filesystem creation events for the specific hardcoded OpenSSL path documented in the VulnCheck advisory
• Alert on module load events where the Konga process maps modules from writable, non-standard locations
• Baseline the installed Konga version and flag hosts running any release below 2.1.0

Monitoring Recommendations

• Enable Windows Sysmon Event ID 11 for file creation and Event ID 7 for image loads within the OpenSSL directory
• Track process creation chains where Konga spawns child processes not observed in prior baselines
• Correlate authentication logs with local file staging activity in known DLL search-order abuse paths

How to Mitigate CVE-2026-45221

Immediate Actions Required

• Upgrade Konga to version 2.1.0 or later on all Windows hosts
• Audit the hardcoded OpenSSL directory on every Konga host and remove unauthorized files or directories
• Restrict the service account used to launch Konga to the minimum privileges needed for operation

Patch Information

Konga 2.1.0 remediates the hardcoded path behavior. Download the fixed release from the Easybyte Archive Download or the vendor site at Easybyte Homepage. Review the VulnCheck Advisory: Konga Privilege Escalation for full remediation guidance.

Workarounds

• Pre-create the hardcoded OpenSSL directory and set an access control list that denies write access to all non-administrative users
• Run Konga under a low-privilege, dedicated service account so that any exploitation does not yield elevated rights
• Apply Windows AppLocker or Windows Defender Application Control policies to block unsigned DLL loads from user-writable paths

# Configuration example: restrict write access on the OpenSSL directory (PowerShell)
New-Item -ItemType Directory -Path 'C:\path\to\openssl' -Force
icacls 'C:\path\to\openssl' /inheritance:r
icacls 'C:\path\to\openssl' /grant:r 'Administrators:(OI)(CI)F' 'SYSTEM:(OI)(CI)F'
icacls 'C:\path\to\openssl' /deny 'Authenticated Users:(OI)(CI)(W,AD)'