HackingGovernmentGovernmentCustomer Data InvolvedData ExfiltratedIdentity (basic)PHILowContained

City of Foster City

bd_9367e9e9e6a46da5 · schema v1 · pii pii-v2

Severity

Low

Discovered

—

Filed

Oct 1, 2026

To disclose

—

Affected

4state residents only

Linked

2 filings

Confidence

69%

Full breach record for City of Foster City →

City of Foster City notified Massachusetts residents that an unauthorized third party accessed certain City systems between February 28, 2026, and March 25, 2026. The investigation determined that personal information, including names and potentially medical information, may have been viewed or acquired. The City engaged a forensic firm, notified law enforcement, and is offering two years of complimentary credit monitoring via Experian IdentityWorks.

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Incident timeline

Feb 28, 2026

Begins

Oct 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

California State AGbd_8e3dfa7594f85b162026-10-15 · +14dCandidate

Name: City of Foster City
norm: city of foster city

Name: City of Foster City
norm: city of foster city
Industry: Governmentllm

Discovered: —
Breach occurred: Feb 28, 2026 – Mar 25, 2026
Materiality determined: —
Notification sent: —
Affected individuals: 4state-resident count only
Data types: Identity (basic)PHI
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Regulator citations: Notified law enforcement

During the incident: Took steps to investigate, secure our systems, and notify law enforcement
Engaged an independent forensic security firm to assist with the investigation
Arranged for a free two-year membership of Experian IdentityWorks Credit 3B
Changes made: Continuing to evaluate additional measures to reduce the likelihood of a similar incident occurring in the future
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 AGOct 1 · first · this page

California State AG+14d

Pattern: first filing Oct 1 (MA), last Oct 15 (CA) — a 14-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/2026-1794-city-of-foster-city/download
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Oct 1, 2026
Raw hash: 600f0c35d4158244f5b82f243c60e6983c53990efc287a7810f4962d1ae9add4

Linked disclosures

Regulatory filings (1) · sorted by filing gap

Reporting entityCity of Foster City

Victim entityCity of Foster City

IncidentUnauthorized Access

Stated responseTook steps to investigate, secure our systems, and notify law enforcement

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancewww.mass.gov