CVE-2026-23843 Overview
CVE-2026-23843 is an Insecure Direct Object Reference (IDOR) vulnerability in teklifolustur_app, a web-based PHP application for creating, managing, and tracking client quotes. The flaw resides in the offer view functionality. Authenticated users can manipulate the offer_id parameter to access offers that belong to other users. The root issue is the absence of authorization checks that verify whether the requested offer belongs to the currently authenticated user. Commit dd082a134a225b8dcd401b6224eead4fb183ea1c contains the patch. The vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key.
Critical Impact
Authenticated attackers can read confidential quotes belonging to other tenants, exposing pricing, customer data, and internal business records.
Affected Products
- teklifolustur_app versions prior to commit dd082a134a225b8dcd401b6224eead4fb183ea1c
- PHP-based quote management deployments using the affected codebase
- Multi-tenant instances sharing the offer view endpoint
Discovery Timeline
- 2026-01-19 - CVE-2026-23843 published to NVD
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2026-23843
Vulnerability Analysis
The vulnerability is an Insecure Direct Object Reference in the offer view component of teklifolustur_app. The application accepts an offer_id parameter from the request and retrieves the corresponding offer record without validating ownership. Any authenticated user can substitute another user's offer_id value and receive that offer's content in the response.
The flaw breaks tenant isolation in a multi-user PHP application. An attacker who registers a low-privilege account gains read access to confidential quote data prepared for other customers. The exposed data can include pricing, line items, contact details, and internal commercial terms.
The attack does not require elevated privileges or user interaction. Network-based access to the application and a valid session are sufficient.
Root Cause
The root cause is missing server-side authorization logic in the offer view handler. The code queries the offer by its identifier alone and does not constrain the query to records owned by the session user. Patch commit dd082a134a225b8dcd401b6224eead4fb183ea1c adds the ownership check that rejects requests where the requested offer does not belong to the authenticated user.
Attack Vector
An attacker authenticates to the application with any valid account. The attacker then issues a request to the offer view endpoint and supplies sequential or guessed numeric values in the offer_id parameter. The server returns offer data without verifying ownership. Enumeration of identifiers exposes the full offer dataset across all tenants.
The vulnerability manifests in the offer view request handler. See the GitHub Security Advisory GHSA-6h9r-mmg3-cg7m and the patch commit for the exact code paths.
Detection Methods for CVE-2026-23843
Indicators of Compromise
- Repeated requests to the offer view endpoint with sequentially incrementing offer_id values from a single session.
- Authenticated users accessing offer_id values that do not appear in their prior creation or update history.
- Anomalous spikes in offer view requests originating from non-administrative accounts.
Detection Strategies
- Inspect web server access logs for high-volume enumeration patterns against the offer view route.
- Correlate session user identifiers with the offer_id values served in responses to detect cross-tenant reads.
- Deploy application-layer rules that flag requests where the response payload owner differs from the session principal.
Monitoring Recommendations
- Enable verbose application logging that records the authenticated user, requested offer_id, and the owning user of each accessed offer.
- Forward application and web server logs to a centralized analytics platform for retention and query.
- Alert on accounts that view more than a defined threshold of distinct offers within a short window.
How to Mitigate CVE-2026-23843
Immediate Actions Required
- Update teklifolustur_app to a build that includes commit dd082a134a225b8dcd401b6224eead4fb183ea1c.
- Audit application logs for prior enumeration of offer_id values and identify potentially exposed offers.
- Notify affected customers if log review confirms unauthorized access to their offer data.
Patch Information
The fix is published in commit dd082a134a225b8dcd401b6224eead4fb183ea1c of the teklifolustur_app repository. The patch adds an authorization check that confirms the requested offer belongs to the authenticated user before returning data. Administrators should rebuild and redeploy from a commit at or after this hash.
Workarounds
- Restrict access to the application to trusted users only until the patch is applied.
- Add a reverse-proxy or web application firewall rule that blocks rapid sequential offer_id enumeration.
- Rotate offer identifiers to non-guessable values such as UUIDs to slow enumeration as a temporary measure.
# Apply the upstream patch
git fetch origin
git checkout dd082a134a225b8dcd401b6224eead4fb183ea1c
# Redeploy the application after the checkout
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
