CVE-2026-30808: Pandora FMS Auth Bypass Vulnerability

CVE-2026-30808 Overview

CVE-2026-30808 is a Session Fixation vulnerability in Pandora FMS that allows an attacker to perform Session Hijacking via a crafted session ID. The flaw affects Pandora FMS versions 777 through 800, the network monitoring and management platform developed by Artica. The vulnerability is tracked under CWE-384: Session Fixation.

An attacker who successfully fixes a victim's session identifier can hijack the authenticated session after the victim logs in. This grants the attacker access to the victim's privileges within the Pandora FMS console.

Critical Impact

Successful exploitation enables full session hijacking, giving an attacker the same access level as the targeted authenticated user, including potential administrative control over monitoring infrastructure.

Affected Products

• Artica Pandora FMS version 777
• Artica Pandora FMS versions between 777 and 800
• Artica Pandora FMS version 800

Discovery Timeline

• 2026-05-12 - CVE-2026-30808 published to NVD
• 2026-05-13 - Last updated in NVD database

Technical Details for CVE-2026-30808

Vulnerability Analysis

The vulnerability stems from improper handling of session identifiers in Pandora FMS. The application accepts a session ID supplied prior to authentication and continues to use that same identifier after the user successfully authenticates. This behavior violates the secure session management principle of regenerating the session ID on privilege boundary changes such as login.

The issue is classified under CWE-384: Session Fixation. Pandora FMS is widely deployed for IT infrastructure monitoring, so hijacked sessions can expose monitoring data, agent configurations, and administrative functions. The EPSS score is 0.011%, indicating low observed exploitation likelihood, but the impact remains significant given the platform's privileged role in enterprise environments.

Root Cause

The root cause is the absence of session identifier regeneration after authentication. When a user logs in, Pandora FMS retains any session ID that was already associated with the browser. An attacker who can plant a known session identifier on the victim's browser, through a crafted link or a related vector, will share that session once the victim authenticates.

Attack Vector

The attack is network-based and requires user interaction. An attacker first obtains or generates a valid session identifier from the Pandora FMS instance. The attacker then induces the victim to load the application with that fixed session ID, typically through a phishing link or a crafted URL containing the identifier. When the victim authenticates, the attacker reuses the same session ID to access the application as the victim.

No public proof-of-concept exploit is currently listed for CVE-2026-30808. See the Pandora FMS Vulnerability Overview for vendor technical details.

Detection Methods for CVE-2026-30808

Indicators of Compromise

• Multiple concurrent authenticated sessions sharing the same session identifier from different source IP addresses or user-agents.
• Authentication events where the post-login session cookie matches a session cookie observed before authentication for the same user.
• Unexpected administrative actions in Pandora FMS audit logs originating from sessions that were idle or unauthenticated minutes earlier.

Detection Strategies

• Inspect Pandora FMS access logs for session IDs reused across distinct client fingerprints, focusing on transitions from unauthenticated to authenticated requests.
• Correlate web server logs with application authentication events to flag cases where the session token does not rotate at login.
• Hunt for inbound URLs containing session parameters such as PHPSESSID directed at the Pandora FMS login endpoint.

Monitoring Recommendations

• Enable verbose authentication and session logging on the Pandora FMS console and forward logs to a centralized SIEM for correlation.
• Alert on geographic or ASN mismatches between pre-authentication and post-authentication requests within the same session.
• Monitor outbound email and web gateways for crafted links containing session parameters targeting internal Pandora FMS hostnames.

How to Mitigate CVE-2026-30808

Immediate Actions Required

• Upgrade Pandora FMS to a version released after 800 that addresses the session fixation flaw, per vendor guidance.
• Force logout of all active Pandora FMS sessions and require users to re-authenticate after applying the update.
• Restrict network access to the Pandora FMS console using firewall rules or VPN-only access while remediation is in progress.

Patch Information

Artica publishes fixes and version information on the Pandora FMS Vulnerability Overview page. Administrators should consult this advisory for the specific fixed release that addresses CVE-2026-30808 and follow the documented upgrade procedure for their deployment.

Workarounds

• Configure the reverse proxy or web server fronting Pandora FMS to strip inbound session cookies on requests to the login endpoint.
• Enforce the Secure, HttpOnly, and SameSite=Strict attributes on session cookies at the proxy layer to reduce exposure to crafted cross-site links.
• Educate Pandora FMS users to access the console only through bookmarked internal URLs and to avoid clicking on emailed links that point to the monitoring platform.

# Example nginx snippet to harden session cookies for Pandora FMS
proxy_cookie_path / "/; HTTPOnly; Secure; SameSite=Strict";
proxy_set_header X-Forwarded-Proto $scheme;

# Strip externally supplied session cookies on the login path
location = /index.php {
    if ($arg_login = "1") {
        proxy_set_header Cookie "";
    }
    proxy_pass http://pandora_backend;
}