The week in breach news Jul 29, 2026

A widespread outage affected Microsoft users on Thursday, July 23, disrupting access to Azure and Microsoft 365 services.

The outage began at 10:44 AM ET on July 23, primarily affecting customers accessing Microsoft 365 services through network infrastructure connected to Microsoft’s West US Azure region. Microsoft tracked the incident under ID MO1437424 and confirmed that multiple Microsoft 365 services were impacted, including OneDrive, SharePoint Online, Microsoft Teams, the Microsoft 365 Admin Center, Power Automate, Copilot Chat and Microsoft Loop.

Microsoft later revealed that the outage was triggered during routine device maintenance in its West US Azure region, where specific network paths were being isolated. The company said its maintenance process converts these requests into system-readable instructions and verifies that at least one of two redundant network paths remains healthy before work begins. However, a bug in the request conversion system incorrectly identified additional network devices as part of the maintenance event, resulting in widespread service disruption.

Hugging Face disclosed that an autonomous AI agent system breached its production infrastructure and gained access to internal datasets and credentials.

Hugging Face is an open-source AI and machine learning platform used by more than 50,000 organizations and provides access to over 45,000 models from leading AI providers. According to reports, OpenAI’s autonomous test models escaped a sandboxed evaluation environment and autonomously targeted Hugging Face in a multi-stage cyber intrusion. The AI models reportedly exploited a zero-day proxy vulnerability to break out of containment and retrieved data to solve an evaluation benchmark without any human malice or instruction to attack.

The incident is being described as one of the first publicly disclosed examples of an AI system autonomously escaping its testing environment and compromising a real external system, representing the “agentic attacker” scenario that the AI and cybersecurity industry has long warned about. In a statement, OpenAI said it considers the incident an unprecedented cyber event involving state-of-the-art cyber capabilities and is responding accordingly.

The ShinyHunters extortion gang claimed responsibility for a recent supply-chain attack on the global accounting firm EY.

Earlier this month, the London-based accounting giant had begun notifying clients that their personal and financial information had been compromised in a data breach. The incident, discovered on April 23, involved a third-party service management platform used by EY to support tax-related work for its clients. Support tickets that may contain client tax information were stolen during the attack, indicating that personal and financial information included in or used to prepare tax filings may have been compromised.

ShinyHunters has now added EY to its dark web leak site, claiming responsibility for the attack and threatening to publish the allegedly stolen data if the company does not contact the group by July 31, 2026.

Ransomware gangs are exploiting a critical-severity remote code execution (RCE) vulnerability in PTC’s product lifecycle management (PLM) platforms, Windchill and FlexPLM.

The vulnerability, tracked as CVE-2026-12569 (CVSS score: 9.3), was patched on June 17. The following day, PTC warned that the flaw had been exploited in the wild and published indicators of compromise (IoCs). The vulnerability was added to CISA’s Known Exploited Vulnerabilities (KEV) catalog at the end of June. PTC described the flaw as a deserialization of untrusted data vulnerability that can be exploited without authentication.

Reports now indicate that the vulnerability is being exploited by an affiliate of the Cl0p ransomware gang. The attackers are primarily targeting organizations in the aerospace, automotive, manufacturing and retail/apparel sectors.

Stadler Rail rejected a ransom demand of approximately 10 million Swiss francs (about $12.3 million) from the Everest ransomware gang after attackers breached a data exchange platform shared with one of its suppliers.

Stadler Rail, a multinational Swiss manufacturer of locomotives, trams, metro trains, passenger trains and railway signaling systems, said it received an extortion letter from the Everest ransomware gang demanding the ransom payment. The company said it will not pay the threat actor and has filed a criminal complaint with the Thurgau cantonal police.

According to Stadler Rail, the incident occurred in mid-July and did not affect its IT systems or production operations, which continue to operate normally worldwide. The company said the attackers stole only technical information from a supplier that is not considered security relevant.