CVE-2026-6001: BAPSİS Authorization Bypass Vulnerability

CVE-2026-6001 Overview

CVE-2026-6001 is an authorization bypass vulnerability affecting ABIS Technology Ltd. Co. BAPSİS. The flaw stems from the application trusting user-controlled identifiers when granting access to protected resources. Attackers can manipulate these trusted identifiers to access or modify data belonging to other users, classified under [CWE-639] Authorization Bypass Through User-Controlled Key. The issue affects all BAPSİS versions prior to v.202604152042. The vulnerability requires network access and user interaction but no prior authentication, making it accessible to external attackers who can lure a user into triggering a crafted request.

Critical Impact
Successful exploitation allows attackers to bypass authorization controls and gain unauthorized read, write, or delete access to resources tied to other user accounts in BAPSİS.

Affected Products

ABIS Technology Ltd. Co. BAPSİS versions before v.202604152042
All deployments exposing BAPSİS endpoints to untrusted networks
Integrations relying on BAPSİS identifier-based access checks

Discovery Timeline

2026-05-12 - CVE-2026-6001 published to NVD
2026-05-12 - Last updated in NVD database

Technical Details for CVE-2026-6001

Vulnerability Analysis

The vulnerability is an Insecure Direct Object Reference (IDOR) pattern in BAPSİS. The application uses identifiers supplied by the client — such as record IDs, user IDs, or session-bound keys — to retrieve and act on backend resources. The authorization layer does not validate whether the authenticated session owns the referenced object. An attacker can substitute another user's identifier in a request and receive or modify that user's data. Because the access decision relies on a trusted identifier rather than a verified ownership check, the exploitation path mirrors the classic [CWE-639] weakness pattern. The vendor advisory tracked by Siber Güvenlik Notification TR-26-0223 documents the affected build threshold.

Root Cause

The root cause is missing server-side authorization enforcement on object references. BAPSİS treats identifiers received from the client as proof of entitlement. Code paths handling resource lookup query the data store directly using the supplied key, skipping a check that ties the resource to the requesting principal. This design fault permits cross-tenant and cross-user access.

Attack Vector

The attack vector is network-based with required user interaction. An attacker crafts a request — typically by modifying an identifier parameter in a URL, form field, or API body — and delivers it to a victim with valid session context, or replays predictable identifiers directly. When the target submits the request, BAPSİS executes the action against the attacker-chosen resource. Impact spans confidentiality, integrity, and availability of records the victim's role can otherwise reach.

No public proof-of-concept code is available for CVE-2026-6001. Technical details are limited to the vendor and national CERT advisory referenced above.

Detection Methods for CVE-2026-6001

Indicators of Compromise

Unexpected access patterns where a single session retrieves records belonging to multiple unrelated user IDs in BAPSİS logs.
HTTP requests showing sequential or enumerated identifier values in path or query parameters within short time windows.
Audit log entries indicating read or write actions on records that do not match the authenticated user's normal scope.

Detection Strategies

Baseline per-user identifier access ranges in BAPSİS and alert on deviations that suggest enumeration of foreign object IDs.
Correlate authentication events with subsequent resource access to flag sessions touching records outside the user's prior history.
Inspect web server and application logs for parameter tampering patterns against BAPSİS endpoints that accept record or user identifiers.

Monitoring Recommendations

Forward BAPSİS application and access logs to a centralized SIEM and retain them long enough to support cross-session correlation.
Implement rate-based alerts on identifier-bearing endpoints to catch automated enumeration.
Review administrative and high-privilege actions daily for anomalous identifier usage until patched.

How to Mitigate CVE-2026-6001

Immediate Actions Required

Upgrade BAPSİS to version v.202604152042 or later as published by ABIS Technology Ltd. Co.
Restrict network exposure of BAPSİS to trusted segments and authenticated VPN paths until patching completes.
Force re-authentication and rotate active session tokens after the upgrade.

Patch Information

ABIS Technology Ltd. Co. resolves CVE-2026-6001 in BAPSİS build v.202604152042. Apply the vendor-supplied update referenced in the Siber Güvenlik Notification TR-26-0223 advisory. Verify the deployed version after upgrade and confirm that authorization checks on identifier-bearing endpoints enforce ownership validation.

Workarounds

Place a reverse proxy or web application firewall in front of BAPSİS and block requests where identifier parameters do not match the authenticated session context.
Limit access to BAPSİS endpoints to internal networks and known client IP ranges while a patch window is scheduled.
Increase audit logging verbosity on object-access endpoints to support post-incident review if exploitation is suspected.

bash

# Example WAF rule concept (ModSecurity-style) to block cross-user ID access
# Adjust SecRule logic to your environment; this is illustrative only.
SecRule REQUEST_URI "@rx /bapsis/.*\?.*(userId|recordId)=([0-9]+)" \
    "id:1026601,phase:2,deny,status:403,\
    chain,msg:'CVE-2026-6001 possible IDOR attempt'"
    SecRule TX:2 "!@streq %{SESSION.user_id}"