CVE-2026-86279: SourceCodester LMS Auth Bypass Vulnerability

CVE-2026-86279 Overview

CVE-2026-86279 is a session fixation vulnerability in SourceCodester Syllabus-Aligned Learning Management & Examination System 1.0. The flaw resides in an unknown function within the auth_process.php file, which handles authentication for the Login component. The application fails to regenerate session identifiers after a user successfully authenticates, allowing an attacker to fix a known session ID on a victim.

The vulnerability is remotely exploitable and requires user interaction to trigger. A public disclosure exists, meaning exploit details are available to any attacker who searches for them. The weakness is classified as [CWE-384] Session Fixation.

Critical Impact

An attacker who successfully fixes a session identifier can hijack an authenticated user's account and access the learning management system with the victim's privileges.

Affected Products

• SourceCodester Syllabus-Aligned Learning Management & Examination System 1.0
• Component: Login (auth_process.php)
• Deployment: Web-hosted PHP application

Discovery Timeline

• 2026-09-07 - CVE-2026-86279 published to the National Vulnerability Database (NVD)
• 2026-09-09 - Last updated in NVD database

Technical Details for CVE-2026-86279

Vulnerability Analysis

The vulnerability affects the login workflow implemented in auth_process.php. When a user submits credentials, the application authenticates the user but does not invalidate or regenerate the existing PHP session identifier. This behavior allows an attacker who provides a session token to the victim in advance to inherit the authenticated session once the victim logs in.

Session fixation is documented under CWE-384. It differs from session hijacking because the attacker supplies the session ID rather than stealing it. Exploitation depends on the attacker delivering a crafted link or cookie to the victim, typically via phishing or a malicious script.

The scope of impact is limited to the confidentiality, integrity, and availability of data accessible to the compromised user account. Because the application is an educational platform, exposed data may include grades, examination content, and personally identifiable information about students and instructors.

Root Cause

The root cause is the absence of a session regeneration call, such as PHP's session_regenerate_id(true), after successful authentication in auth_process.php. Without this call, the session identifier presented before login remains valid after login, breaking the trust boundary between anonymous and authenticated states.

Attack Vector

An attacker first obtains a valid session identifier by visiting the target application. The attacker then delivers this identifier to the victim, for example through a crafted URL containing a PHPSESSID parameter or through a script that sets the cookie. When the victim logs in using the fixed session ID, the attacker's session becomes authenticated and inherits the victim's access rights. Refer to the GitHub Vulnerability Report for the disclosed proof-of-concept walkthrough.

Detection Methods for CVE-2026-86279

Indicators of Compromise

• Multiple distinct source IP addresses using the same PHPSESSID cookie value against auth_process.php within a short window.
• Successful login events where the session identifier presented before authentication matches the identifier used after authentication.
• Inbound requests to the login page containing a PHPSESSID value in the query string or Referer header.

Detection Strategies

• Enable verbose web server access logging and correlate session cookie values across pre-login and post-login requests.
• Alert when a single session identifier is observed from geographically dispersed IP addresses or user agents.
• Review application logs for authentication events that do not include a session regeneration entry.

Monitoring Recommendations

• Forward web access logs and PHP application logs to a centralized analytics platform for correlation.
• Monitor phishing indicators such as inbound emails containing links to the learning management system with embedded session parameters.
• Track anomalous access to administrative or grading functions immediately following a login event.

How to Mitigate CVE-2026-86279

Immediate Actions Required

• Restrict public exposure of the affected application until a patched build is available.
• Invalidate all active user sessions and require users to reauthenticate.
• Configure PHP session cookies with the HttpOnly, Secure, and SameSite=Strict attributes to reduce cookie exposure.

Patch Information

No vendor patch for SourceCodester Syllabus-Aligned Learning Management & Examination System 1.0 is referenced in the advisory sources. Administrators should track the VulDB CVE-2026-86279 entry and the SourceCodester Security Resource for updates. In the absence of an official fix, apply the source-level workaround described below.

Workarounds

• Modify auth_process.php to call session_regenerate_id(true) immediately after credential validation succeeds, discarding the prior session identifier.
• Reject any PHPSESSID value supplied through URL parameters and enforce cookie-only session transport by setting session.use_only_cookies = 1 in php.ini.
• Set a short session idle timeout and bind sessions to attributes such as the client IP address or user agent to limit reuse.
• Place the application behind a web application firewall configured to strip session identifiers from query strings on login endpoints.

# Configuration example: PHP session hardening in php.ini
session.use_only_cookies = 1
session.use_strict_mode = 1
session.cookie_httponly = 1
session.cookie_secure = 1
session.cookie_samesite = "Strict"