CVE-2026-25060: OpenList Frontend MitM Vulnerability

CVE-2026-25060 Overview

OpenList Frontend is a UI component for OpenList that prior to version 4.1.10 contains a critical security misconfiguration where TLS certificate verification is disabled by default for all storage driver communications. The TlsInsecureSkipVerify setting defaults to true in the DefaultConfig() function located in internal/conf/config.go. This vulnerability enables Man-in-the-Middle (MitM) attacks by disabling TLS certificate verification, allowing attackers to intercept and manipulate all storage communications.

Attackers can exploit this through network-level attacks like ARP spoofing, rogue Wi-Fi access points, or compromised internal network equipment to redirect traffic to malicious endpoints. Since certificate validation is skipped, the system will unknowingly establish encrypted connections with attacker-controlled servers, enabling full decryption, data theft, and manipulation of all storage operations without triggering any security warnings.

Critical Impact

This vulnerability allows attackers to perform Man-in-the-Middle attacks on all storage communications, enabling data theft, manipulation, and interception of sensitive information without detection.

Affected Products

• OpenList Frontend versions prior to 4.1.10
• OpenList storage driver communications
• Systems using default OpenList configuration

Discovery Timeline

• 2026-02-02 - CVE-2026-25060 published to NVD
• 2026-02-03 - Last updated in NVD database

Technical Details for CVE-2026-25060

Vulnerability Analysis

This vulnerability stems from an insecure default configuration in OpenList Frontend where TLS certificate verification is intentionally disabled. The TlsInsecureSkipVerify parameter is set to true by default in the DefaultConfig() function within internal/conf/config.go. This configuration affects all storage driver communications, meaning every connection made to storage backends operates without validating the authenticity of the server certificates.

The vulnerability is classified under CWE-599 (Missing Validation of OpenSSL Certificate), which highlights the failure to properly validate cryptographic certificates. When certificate validation is disabled, the application accepts any certificate presented by a server, including self-signed, expired, or certificates issued by untrusted certificate authorities. This completely undermines the security guarantees of TLS encryption.

Root Cause

The root cause lies in the insecure default configuration where TlsInsecureSkipVerify is set to true in the DefaultConfig() function. This design decision prioritizes ease of initial setup over security, allowing deployments to connect to storage backends without proper certificate validation. The configuration file at internal/conf/config.go contains this dangerous default that effectively nullifies TLS security for all storage communications.

Attack Vector

The attack vector is network-based, requiring the attacker to position themselves between the OpenList instance and its storage backends. Attackers can exploit this vulnerability through multiple techniques:

1. ARP Spoofing: Manipulating ARP tables on the local network to redirect traffic
2. Rogue Wi-Fi Access Points: Setting up malicious access points that intercept communications
3. DNS Spoofing: Redirecting storage endpoint domain names to attacker-controlled servers
4. Compromised Network Equipment: Leveraging access to routers or switches to intercept traffic

Once positioned, attackers can intercept all storage communications, decrypt the traffic, steal sensitive data, modify data in transit, and inject malicious content—all without triggering any security warnings in the application.

The following code example shows the security patch that addresses this vulnerability:

 		}
 	}
 	configPath = filepath.Clean(configPath)
+	conf.ConfigPath = configPath
 	log.Infof("reading config file: %s", configPath)
 	if !utils.Exists(configPath) {
 		log.Infof("config file not exists, creating default config file")

Source: GitHub Commit Update

The patch also introduces a configuration reset function to ensure existing installations are updated:

 		Version: "v4.1.9",
 		Patches: []func(){
 			v4_1_9.EnableWebDavProxy,
+			v4_1_9.ResetSkipTlsVerify,
 		},
 	},
}

Source: GitHub Commit Update

Detection Methods for CVE-2026-25060

Indicators of Compromise

• Unexpected certificate warnings or errors in network monitoring tools when analyzing OpenList traffic
• Configuration files showing TlsInsecureSkipVerify: true in OpenList deployments
• Network traffic to storage backends that accepts certificates from unexpected certificate authorities
• Anomalous storage backend responses or data integrity issues indicating potential MitM activity

Detection Strategies

• Review OpenList configuration files for the TlsInsecureSkipVerify setting and ensure it is set to false
• Monitor network traffic for TLS connections that do not perform proper certificate validation handshakes
• Implement network intrusion detection rules to identify potential ARP spoofing or DNS spoofing attacks targeting OpenList storage communications
• Deploy certificate transparency monitoring for any certificates being used in storage communications

Monitoring Recommendations

• Enable detailed logging for all storage driver connections and monitor for certificate-related warnings
• Implement network segmentation to isolate OpenList instances and storage backends from untrusted network segments
• Configure alerting for any configuration changes to TLS-related settings in OpenList
• Deploy network monitoring solutions capable of detecting man-in-the-middle attack patterns

How to Mitigate CVE-2026-25060

Immediate Actions Required

• Upgrade OpenList Frontend to version 4.1.10 or later immediately
• Audit current configuration files to identify if TlsInsecureSkipVerify is set to true and change it to false
• Review network architecture to ensure OpenList instances communicate with storage backends over trusted network segments
• Implement certificate pinning where possible for critical storage endpoints

Patch Information

The vulnerability is fixed in OpenList Frontend version 4.1.10. The patch modifies the default configuration behavior and introduces the ResetSkipTlsVerify function to ensure existing installations have secure defaults applied during the upgrade process. Users should upgrade to version 4.1.10 or later, which is available on the GitHub Release page. Additional details about the vulnerability can be found in the GitHub Security Advisory GHSA-wf93-3ghh-h389.

Workarounds

• Manually set TlsInsecureSkipVerify to false in the configuration file at internal/conf/config.go
• Implement network-level controls such as VPNs or private network segments to reduce the risk of MitM attacks
• Deploy a reverse proxy with proper TLS termination and certificate validation in front of OpenList
• Use firewall rules to restrict storage backend access to only trusted IP addresses

# Configuration example
# Ensure TLS certificate verification is enabled in OpenList configuration
# Edit your config file (typically config.json or config.yaml)
# Set TlsInsecureSkipVerify to false:

# For JSON configuration:
# "tls_insecure_skip_verify": false

# For YAML configuration:
# tls_insecure_skip_verify: false

# After modifying configuration, restart the OpenList service
systemctl restart openlist