CVE-2026-82764 Overview
CVE-2026-82764 is a Cross-Site Request Forgery (CSRF) vulnerability affecting multiple Contec products. An authenticated user who views a specially crafted page while logged into an affected product may trigger unintended operations on that product. The flaw is tracked under CWE-352: Cross-Site Request Forgery.
Contec has published three separate security information documents covering the affected CPS, FL, and PH product lines. The Japan Vulnerability Notes (JVN) portal has issued three coordinated advisories referencing this issue.
Critical Impact
An attacker who convinces an authenticated administrator to load a malicious page can perform unintended state-changing operations on the affected Contec device.
Affected Products
- Multiple Contec CPS series products (see Contec security document contec_security_cps_26091000_en.pdf)
- Multiple Contec FL series products (see Contec security document contec_security_fl_26091000_en.pdf)
- Multiple Contec PH series products (see Contec security document contec_security_ph_26091000_en.pdf)
Discovery Timeline
- 2026-09-14 - CVE-2026-82764 published to the National Vulnerability Database
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-82764
Vulnerability Analysis
The vulnerability is a classic Cross-Site Request Forgery weakness in the web management interface of the affected Contec products. The application accepts state-changing HTTP requests without validating that the request originated from an intentional user action within its own interface. An attacker who lures an authenticated user to a malicious page can cause the browser to submit forged requests using the victim's active session.
Exploitation requires user interaction: the victim must be logged in and must load attacker-controlled web content. No credentials or privileges are needed by the attacker on the target device itself. Impact is limited to operations available to the victim's authenticated role.
Root Cause
The affected web interfaces do not enforce anti-CSRF protections on sensitive endpoints. Typical missing controls include per-request synchronizer tokens, SameSite cookie attributes, and validation of the Origin or Referer header. Without these controls, the browser transparently attaches session cookies to any request the attacker's page issues to the device.
Attack Vector
Exploitation follows the standard CSRF pattern. The attacker hosts a page containing an HTML form or JavaScript that auto-submits a request to a known endpoint on the Contec device. When the authenticated victim visits the page, the browser sends the request with valid session credentials, and the device executes the operation as if the user had performed it. The vulnerability is network-reachable when the victim's browser has network access to the device, including internal management networks.
No verified proof-of-concept exploit code has been published. Refer to JVN Security Advisory JVNVU90314828, JVNVU96551518, and JVNVU99009004 for further coordinated disclosure detail.
Detection Methods for CVE-2026-82764
Indicators of Compromise
- Unexpected configuration or state changes on Contec devices that correlate with a user's active administrative session.
- HTTP requests to device management endpoints whose Referer or Origin header points to an external, unrelated domain.
- Web server logs showing state-changing POST or GET requests without an associated interactive navigation sequence from the management UI.
Detection Strategies
- Inspect device access logs for requests originating from browsers where the Referer header does not match the device's own management URL.
- Correlate administrator browsing telemetry with device configuration change events to identify requests triggered by third-party pages.
- Monitor for phishing or watering-hole content that references known Contec management endpoints or IP ranges.
Monitoring Recommendations
- Enable and centralize logging from Contec web management interfaces where supported.
- Alert on configuration changes performed outside normal maintenance windows.
- Track outbound web browsing by operators of industrial and control-system equipment and flag unapproved destinations.
How to Mitigate CVE-2026-82764
Immediate Actions Required
- Apply the updates and workarounds documented in the vendor security bulletins for the CPS, FL, and PH product families.
- Restrict management interface access to a dedicated, isolated administrative network segment.
- Require operators to log out of the device web interface immediately after administrative tasks and to avoid general web browsing from the same browser session.
Patch Information
Contec has released security information documents for the affected product families. Review the vendor advisories for version-specific fixes: Contec Security Information for CPS, Contec Security Information for FL, and Contec Security Information for PH.
Workarounds
- Access the device management interface only from a dedicated administrative workstation that is not used for general web browsing or email.
- Enforce network-level access controls so the device management interface is unreachable from user workstations except during scheduled maintenance.
- Configure browsers used for administration to block third-party cookies and cross-site requests where feasible.
- Terminate the authenticated session by logging out immediately after each administrative task.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
