HackingProfessional ServicesFinancial ServicesProfessional ServicesStolen CredentialsSupply Chain (3P Vendor)Data ExfiltratedCustomer Data InvolvedPIIIdentity (basic)LowContained

Tishman Speyer

bd_291b5b6f1b2fa808 · schema v1 · pii pii-v2

Severity

Low

Discovered

Apr 23, 2026

Filed

Sep 1, 2026

To disclose

—

Affected

24state residents only

Linked

2 filings

Confidence

68%

Full breach record for Tishman Speyer →

Ernst & Young LLP (EY) notified Tishman Speyer investors of a data breach involving EY's third-party IT service management platform. Between March 28 and April 12, 2026, an unauthorized third party accessed the platform and downloaded documents containing client tax information and PII. EY detected anomalous activity on April 23, 2026. Tishman Speyer's internal systems were not impacted. EY engaged forensic investigators, contained the breach, and notified law enforcement. Affected individuals are offered 24 months of credit monitoring.

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Incident timeline

undetected · 26 days

Mar 28, 2026

Begins

Apr 23, 2026

Discovered

Sep 1, 2026

Filed

This filing is one of 2 filings about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (1) · sorted by filing gap

Indiana State AGbd_0378e1316a841fca2026-09-16 · +15dVerified

Name: ERNST & YOUNG LLP
norm: ernst young
Domain: ey.com

Name: Tishman Speyer
norm: tishman speyer
Industry: Professional ServicesllmFinancial Servicesllm

Discovered: Apr 23, 2026
Breach occurred: Mar 28, 2026 – Apr 12, 2026
Undetected for: 26 daysoccurrence → discovery
Materiality determined: —
Notification sent: —
Affected individuals: 24state-resident count only
Data types: PIIIdentity (basic)
Attack vector: Third-Party / Supply Chain
MITRE ATT&CK: T1078 Valid AccountsT1041 Exfiltration Over C2 Channel
Threat actor: External
Regulator citations: Notified federal law enforcementNotified the data protection authority in your jurisdiction
Third party: via Third-party information technology service management platform provider

During the incident: Initiated incident response procedure to determine the nature and scope of the incident, contain it, and begin remediation and recovery efforts
Worked with an independent cybersecurity firm to investigate the incident
Confirmed that the unauthorized access has been stopped
Notified federal law enforcement of this incident
Notified Tishman Speyer that information related to Tishman Speyer investors may have been impacted
Offering complimentary access to Experian IdentityWorks and Identity Restoration services
Source: Quoted from the filing itself, not independently verified.

Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 2 filings · 2 states

View merged incident ↗

Massachusetts State AGSep 1 · first · this page

Indiana State AG+15d

Pattern: first filing Sep 1 (MA), last Sep 16 (IN) — a 15-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

Evidence ladder

Leak-site claim

Attacker assertion only. Establishes: claim date, group, alleged victim.

Press / market report

Unlocks: incident narrative, operational impact. Still no compliance clock.

State AG / regulator filingThis record

Unlocks: discovery date, data types, affected count, compliance clock.

SEC 8-K / victim statement

Unlocks: materiality, stated response, full audit trail. Ceiling removed.

Source URL: https://www.mass.gov/doc/2026-1568-tishman-speyer/download
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Sep 1, 2026
Raw hash: 2ee503326ac797eb7615b95328843ce8aefab7346e24e65368ea73eabda0d721

Linked disclosures

Regulatory filings (1) · sorted by filing gap

Reporting entityERNST & YOUNG LLP

Victim entityTishman Speyer

Incidentdiscovered Apr 23, 2026

Stated responseInitiated incident response procedure to determine the nature and scope of the incident, contain it, and begin remediation and recovery efforts

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancewww.mass.gov