CVE-2026-78115: Class Timetabling System Auth Bypass Flaw

CVE-2026-78115 Overview

CVE-2026-78115 is an improper authorization vulnerability [CWE-266] in SourceCodester Class and Exam Timetabling System 1.0. The flaw resides in the /admin/edit_user_account.php endpoint, which handles the User Account Update component. An authenticated attacker with low privileges can manipulate the id or username parameter to modify accounts they should not have access to. The attack is remotely exploitable over the network and requires no user interaction. Public disclosure of the exploit technique has occurred, increasing the risk of opportunistic abuse against exposed installations.

Critical Impact
Authenticated attackers can alter other users' account records through the edit_user_account.php endpoint, undermining integrity and availability of user account data.

Affected Products

SourceCodester Class and Exam Timetabling System 1.0
Component: User Account Update (/admin/edit_user_account.php)
Affected parameters: id, username

Discovery Timeline

2026-08-23 - CVE-2026-78115 published to NVD
2026-08-26 - Last updated in NVD database

Technical Details for CVE-2026-78115

Vulnerability Analysis

The vulnerability is classified under [CWE-266: Incorrect Privilege Assignment]. The /admin/edit_user_account.php script fails to verify whether the requesting session has the authority to modify the account identified by the supplied id or username parameter. As a result, any authenticated user who can reach the endpoint can submit update requests targeting arbitrary accounts. Attackers can leverage this to change credentials, escalate their access, or corrupt records for legitimate users. The exploit path is straightforward and does not require chained bugs, memory corruption primitives, or client-side interaction.

Root Cause

The root cause is a missing authorization check on the account update handler. The application trusts the values supplied in the id and username request parameters and uses them to select the target account without validating that the authenticated session owns the record or holds the administrative role required to modify it. Access control is enforced only at the page level rather than at the object level.

Attack Vector

Exploitation requires network access to the application and a valid low-privilege account. The attacker submits a crafted POST or GET request to /admin/edit_user_account.php supplying the target account identifier and desired field values. Because the disclosure is public, automated scanning against Internet-exposed instances is feasible. Refer to the VulDB CVE-2026-78115 Details and the GitHub Repository for CVE-2026 for the disclosed technical write-up.

Detection Methods for CVE-2026-78115

Indicators of Compromise

Unexpected HTTP requests to /admin/edit_user_account.php originating from non-administrative user sessions.
Modifications to user records where the acting session identity does not match the target id or username.
Sudden password or role changes on accounts without corresponding administrator audit trail entries.

Detection Strategies

Enable verbose access logging on the admin directory and alert on requests to edit_user_account.php that carry mismatched session and parameter identities.
Correlate web server logs with application audit logs to identify low-privilege sessions issuing account-modification requests.
Deploy a web application firewall rule to flag or block requests that supply an id parameter differing from the session-bound user identifier.

Monitoring Recommendations

Monitor for bursts of requests to account management endpoints from a single session or IP address.
Track the EPSS trend for CVE-2026-78115, currently reported at 0.296% (percentile 21.7) as of 2026-08-27, to detect changes in exploitation likelihood.
Review database change logs on the users table for edits not attributable to administrator activity.

How to Mitigate CVE-2026-78115

Immediate Actions Required

Restrict access to /admin/ paths using network controls or authentication proxies until the application is patched.
Audit all user accounts for unauthorized modifications, particularly password resets and role changes.
Rotate credentials for privileged accounts that could have been targeted through the improper authorization flaw.

Patch Information

No vendor patch is listed in the NVD or VulDB entries at the time of publication. Operators should track the SourceCodester Security Resource and the VulDB Vulnerability #394515 record for remediation updates. Custom code fixes should add server-side ownership checks in edit_user_account.php that compare the session-bound user identifier to the record being modified and enforce role checks for administrative updates.

Workarounds

Place the application behind an authenticated reverse proxy that limits /admin/ access to trusted administrator source addresses.
Add a server-side authorization filter that rejects update requests where the session role is not administrator and the requested id does not match the session user.
Disable the user account update feature if administrative account management can be performed through direct database access during the mitigation window.

bash

# Example nginx restriction limiting /admin/ to trusted networks
location /admin/ {
    allow 10.0.0.0/8;
    deny  all;
    auth_basic "Restricted";
    auth_basic_user_file /etc/nginx/.htpasswd;
}