What happened
Ubisoft’s popular online shooter Rainbow Six Siege suffered a significant security breach on December 27, 2025, that allowed unauthorized actors to manipulate internal backend systems. Attackers flooded player accounts with approximately 2 billion R6 Credits and Renown, unlocked exclusive cosmetics (including developer-only items), and triggered erroneous ban/unban activity across the game’s live services. Ubisoft acknowledged the incident and took Rainbow Six Siege and its in-game Marketplace offline to contain the issue. The company has begun rolling back transactions made since 11:00 AM UTC and stated that players will not be punished for spending credits received during the incident.
Who is affected
The breach impacted Rainbow Six Siege players globally on PC, PlayStation, and Xbox platforms, from casual gamers to high-profile streamers, with reports of even official Ubisoft accounts showing altered balances and ban states. The in-game economy and live services were disrupted, leading to widespread confusion and temporary service outages while Ubisoft works on remediation.
Why CISOs should care
This incident highlights critical lessons for security leaders:
- Backend system exposure: Even when client-side protections are in place, insecure server-side APIs and internal tools can be exploited at scale.
- Operational impact: Large-scale breaches can disrupt services for millions of users and damage trust with stakeholders and customers.
- Incident ambiguity: Early reporting includes unverified claims, underscoring the importance of rapid forensic investigation and clear communication during crisis response.
3 practical actions for CISOs
- Review internal API security and access controls: Ensure robust authentication, authorization, and monitoring for all backend endpoints, particularly those capable of altering digital assets or user state.
- Implement zero-trust controls for internal tools: Enforce least-privilege access, multi-factor authentication, and segmented environments to reduce the attack surface for internal system abuse.
- Prepare incident response playbooks for live-service breaches: Maintain up-to-date plans that cover communication protocols, rollback strategies, and coordination with engineering, legal, and public relations teams to manage breach fallout effectively.