PTC Windchill Product Lifecycle Management

Summary

A critical remote code execution (RCE) vulnerability (CVE-2026-4681) has been disclosed in PTC Windchill PDMLink and FlexPLM product lifecycle management systems through unsafe deserialization of untrusted data, affecting versions 11.0 through 13.1.3.0 across both products with a CVSS score of 10. PTC is actively developing patches while recommending immediate implementation of HTTP server configuration workarounds for all deployments, with particular urgency for publicly exposed instances. This vulnerability impacts critical manufacturing infrastructure worldwide, with no known public exploitation reported at the time of disclosure.

Full text

ICS Advisory PTC Windchill Product Lifecycle Management Release DateMarch 26, 2026 Alert CodeICSA-26-085-03 Related topics: Industrial Control System Vulnerabilities, Industrial Control Systems View CSAF Summary Successful exploitation of this vulnerability could allow an attacker to achieve remote code execution. The following versions of PTC Windchill Product Lifecycle Management are affected: Windchill PDMLink 11.0_M030 (CVE-2026-4681) Windchill PDMLink 11.1_M020 (CVE-2026-4681) Windchill PDMLink 11.2.1.0 (CVE-2026-4681) Windchill PDMLink 12.0.2.0 (CVE-2026-4681) Windchill PDMLink 12.1.2.0 (CVE-2026-4681) Windchill PDMLink 13.0.2.0 (CVE-2026-4681) Windchill PDMLink 13.1.0.0 (CVE-2026-4681) Windchill PDMLink 13.1.1.0 (CVE-2026-4681) Windchill PDMLink 13.1.2.0 (CVE-2026-4681) Windchill PDMLink 13.1.3.0 (CVE-2026-4681) FlexPLM 11.0_M030 (CVE-2026-4681) FlexPLM 11.1_M020 (CVE-2026-4681) FlexPLM 11.2.1.0 (CVE-2026-4681) FlexPLM 12.0.0.0 (CVE-2026-4681) FlexPLM 12.0.2.0 (CVE-2026-4681) FlexPLM 12.0.3.0 (CVE-2026-4681) FlexPLM 12.1.2.0 (CVE-2026-4681) FlexPLM 12.1.3.0 (CVE-2026-4681) FlexPLM 13.0.2.0 (CVE-2026-4681) FlexPLM 13.0.3.0 (CVE-2026-4681) CVSS Vendor Equipment Vulnerabilities v3 10 PTC PTC Windchill Product Lifecycle Management Improper Control of Generation of Code ('Code Injection') Background Critical Infrastructure Sectors: Critical Manufacturing Countries/Areas Deployed: Worldwide Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2026-4681 A critical remote code execution (RCE) vulnerability has been reported in PTC Windchill and PTC FlexPLM. The vulnerability may be exploited through the deserialization of untrusted data. This issue affects Windchill PDMLink: 11.0 M030, 11.1 M020, 11.2.1.0, 12.0.2.0, 12.1.2.0, 13.0.2.0, 13.1.0.0, 13.1.1.0, 13.1.2.0, 13.1.3.0; FlexPLM: 11.0 M030, 11.1 M020, 11.2.1.0, 12.0.0.0, 12.0.2.0, 12.0.3.0, 12.1.2.0, 12.1.3.0, 13.0.2.0, 13.0.3.0. View CVE Details Affected Products PTC Windchill Product Lifecycle Management Vendor:PTC Product Version:PTC Windchill PDMLink: 11.0_M030, PTC Windchill PDMLink: 11.1_M020, PTC Windchill PDMLink: 11.2.1.0, PTC Windchill PDMLink: 12.0.2.0, PTC Windchill PDMLink: 12.1.2.0, PTC Windchill PDMLink: 13.0.2.0, PTC Windchill PDMLink: 13.1.0.0, PTC Windchill PDMLink: 13.1.1.0, PTC Windchill PDMLink: 13.1.2.0, PTC Windchill PDMLink: 13.1.3.0, PTC FlexPLM: 11.0_M030, PTC FlexPLM: 11.1_M020, PTC FlexPLM: 11.2.1.0, PTC FlexPLM: 12.0.0.0, PTC FlexPLM: 12.0.2.0, PTC FlexPLM: 12.0.3.0, PTC FlexPLM: 12.1.2.0, PTC FlexPLM: 12.1.3.0, PTC FlexPLM: 13.0.2.0, PTC FlexPLM: 13.0.3.0 Product Status:known_affected Remediations MitigationPTC is aware of the issue and is actively developing a fix. In the meantime, PTC recommends applying the recommended workaround. Until official patches are available, customers must take urgent steps to safeguard their environments. Specifically: Protect any publicly accessible Windchill systems Vendor fixWhile publicly accessible Windchill and FlexPLM systems are at higher risk and require immediate attention, PTC strongly recommends applying the mitigation steps to all deployments, regardless of Internet exposure Vendor fixApply the same precautions to FlexPLM deployments Vendor fixThe following Apache and IIS HTTP Server configuration update should be IMMEDIATELY applied to every Windchill or FlexPLM system: Customers using Apache HTTP Server should only follow "Apache HTTP Server Configuration – Workaround Steps" section steps MitigationCustomers using Microsoft IIS should only follow "IIS Configuration - Workaround Steps" section steps MitigationPlease explicitly note that the same mitigation steps must also be applied on File Server / Replica Server configurations where applicable MitigationFor Windchill releases prior to 11.0 M030, workarounds may need to be altered to apply to unsupported previous releases MitigationFor Apache HTTP Server and IIS configuration workaround steps, please refer to the official advisory at:https://www.ptc.com/en/about/trust-center/advisory-center/active-advisories/windchill-flexplm-critical-vulnerability.https://www.ptc.com/en/about/trust-center/advisory-center/active-advisories/windchill-flexplm-critical-vulnerability MitigationIf immediate remediation is not feasible, additional guidance and remediation options are available:https://www.ptc.com/en/about/trust-center/advisory-center/active-advisories/windchill-flexplm-critical-vulnerability.https://www.ptc.com/en/about/trust-center/advisory-center/active-advisories/windchill-flexplm-critical-vulnerability Relevant CWE: CWE-94 Improper Control of Generation of Code ('Code Injection') Metrics CVSS Version Base Score Base Severity Vector String 3.1 10 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H Acknowledgments An anonymous source reported this vulnerability to CISA Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. Revision History Initial Release Date: 2026-03-26 Date Revision Summary 2026-03-26 1 Initial Republication of PTC's CS466318 Legal Notice and Terms of Use This product is provided subject to this Notification and this Privacy & Use policy. Vendor PTC Tags Sector: Critical Manufacturing Sector Topics: Industrial Control System Vulnerabilities, Industrial Control Systems Please share your thoughts We recently updated our anonymous product survey; we welcome your feedback. Related Advisories Mar 26, 2026 ICS Advisory | ICSA-26-085-02 OpenCode Systems OC Messaging and USSD Gateway Mar 26, 2026 ICS Advisory | ICSA-26-085-01 WAGO GmbH & Co. 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Indicators of Compromise

• cve — CVE-2026-4681