Marsh McLennan
Company Details
Linkedin ID:
marshmclennan
Website:
Employees number:
67,727
Number of followers:
810,970
NAICS:
52
Industry Type:
Homepage:
marshmclennan.com
IP Addresses:
526
Company ID:
MAR_2333270
Scan Status:
Completed
Marsh McLennan Company CyberSecurity Posture
marshmclennan.com
Marsh McLennan (NYSE: MMC) is a global leader in risk, strategy and people, advising clients in 130 countries across four businesses: Marsh, Guy Carpenter, Mercer and Oliver Wyman. With annual revenue of $23 billion and more than 85,000 colleagues, Marsh McLennan helps build the confidence to thrive through the power of perspective. Follow us on X at @MarshMcLennan.
Marsh McLennan A.I CyberSecurity Scoring
Marsh McLennan Risk Score (AI oriented)Between 750 and 799
Marsh McLennan
Updated:
- Powered by our proprietary A.I cyber incident model
- Insurance preferes TPRM score to calculate premium
Marsh McLennan Global Score (TPRM)XXXX
Marsh McLennan
- Instant access to detailed risk factors
- Benchmark vs. industry & size peers
- Vulnerabilities
- Findings
Marsh McLennan Company CyberSecurity News & History
Past Incidents
3
Attack Types
2
Marsh & McLennan Companies, Inc.
Breach
Rankiteo Explanation
Attack with significant impact with internal employee data leaks
Description: The California Office of the Attorney General reported a data breach involving Kroll Background Screening Services, a subsidiary of Marsh & McLennan Companies, Inc. The breach occurred between June 2013 and September 2013, resulting in unauthorized access to personal information, including names and Social Security Numbers. The breach notification was reported on November 26, 2013.
Marsh McLennan
Breach
Rankiteo Explanation
Attack with significant impact with customers data leaks
Description: The Washington State Office of the Attorney General reported that Marsh McLennan experienced a cyberattack involving unauthorized access to personal information on April 22, 2021, which was discovered on April 26, 2021. The breach potentially affected 2,550 Washington residents, with compromised information including names, Social Security numbers, driver's license numbers, and health insurance information. Notifications to affected individuals began on June 30, 2021.
Marsh McLennan
Data Leak
Rankiteo Explanation
Attack limited on finance or reputation
Description: Marsh & McLennan Cos. Inc. was hit by a data breach in April involving access to Social Security numbers and other personal information of staff, former staff, clients and a range of other people linked to the brokerage. Marsh McLennan notified that the breach involved a limited set of data and it reset system access rights and imposed additional restrictions. The information involved included names, Social Security numbers or other federal tax identification numbers. The company offered complimentary credit monitoring for two years, identity theft detection and resolution services and up to $1 million in identity theft insurance coverage.
Marsh McLennan Company Scoring based on AI Models
Cyber Incidents Likelihood 3 - 6 - 9 months
A.I Risk Score Likelihood 3 - 6 - 9 months
Underwriter Stats for Marsh McLennan
Incidents vs Financial Services Industry Average (This Year)
No incidents recorded for Marsh McLennan in 2025.
Incidents vs All-Companies Average (This Year)
No incidents recorded for Marsh McLennan in 2025.
Incident Types Marsh McLennan vs Financial Services Industry Avg (This Year)
No incidents recorded for Marsh McLennan in 2025.
Incident History — Marsh McLennan (X = Date, Y = Severity)
Marsh McLennan cyber incidents detection timeline including parent company and subsidiaries
Marsh McLennan Company Subsidiaries
Marsh McLennan (NYSE: MMC) is a global leader in risk, strategy and people, advising clients in 130 countries across four businesses: Marsh, Guy Carpenter, Mercer and Oliver Wyman. With annual revenue of $23 billion and more than 85,000 colleagues, Marsh McLennan helps build the confidence to thrive through the power of perspective. Follow us on X at @MarshMcLennan.
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Marsh McLennan CyberSecurity News
November 09, 2025 04:37 PM
Ransomware Surge Poses Geopolitical and Economic Risks, Warns Joint Cybersecurity Report
A new joint report released this week by Northwave Cyber Security and Marsh, a division of Marsh McLennan, warns that ransomware attacks...
September 30, 2025 07:00 AM
Risk in Context Podcast: Strengthening resilience through effective cyber threat management
In this episode our hosts discuss the importance of reviewing and reinforcing cyber controls to help minimize cyber exposures and...
September 01, 2025 07:00 AM
Incident response, MFA, and EDR rank as top controls in Marsh McLennan’s latest cyber risk study
Marsh McLennan, through its Cyber Risk Intelligence Center, examines which cybersecurity measures actually reduce risk and pushes the...
September 01, 2025 07:00 AM
Cybersecurity signals: Connecting controls and incident outcomes
Cybersecurity signals research highlights the controls that most reduce breach risk and shows why deployment quality is key to outcomes.
August 29, 2025 07:00 AM
Global: Incident response planning is a vital cybersecurity control in reducing cyber risk
Cyber incident response planning has emerged as an important cybersecurity control in reducing an organisation's likelihood of experiencing...
August 28, 2025 07:00 AM
Incident response planning linked to fewer cyber insurance claims: Marsh
Organizations that regularly test their cyber incident response plans are significantly less likely to face breach-related insurance claims,...
August 27, 2025 07:00 AM
Cybersecurity signals: Connecting controls and incident outcomes
This study analyzes data and explores which cybersecurity controls are most effective at reducing risk.
August 27, 2025 07:00 AM
Marsh McLennan Cyber Risk Intelligence Center report
Proactive cyber incident response planning reduces breach claims by 13%, with effective controls like EDR and MFA further lowering cyber...
August 27, 2025 07:00 AM
Incident response planning cuts the risk of claiming on cyber security insurance
Proper attention to incident response planning is emerging as a core cyber control when it comes to reducing the risk of having to claim on...
Frequently Asked Questions
Explore insights on cybersecurity incidents, risk posture, and Rankiteo's assessments.
Marsh McLennan CyberSecurity History Information
Official Website of Marsh McLennan
The official website of Marsh McLennan is https://www.marshmclennan.com/.
Marsh McLennan’s AI-Generated Cybersecurity Score
According to Rankiteo, Marsh McLennan’s AI-generated cybersecurity score is 792, reflecting their Fair security posture.
How many security badges does Marsh McLennan’ have ?
According to Rankiteo, Marsh McLennan currently holds 0 security badges, indicating that no recognized compliance certifications are currently verified for the organization.
Does Marsh McLennan have SOC 2 Type 1 certification ?
According to Rankiteo, Marsh McLennan is not certified under SOC 2 Type 1.
Does Marsh McLennan have SOC 2 Type 2 certification ?
According to Rankiteo, Marsh McLennan does not hold a SOC 2 Type 2 certification.
Does Marsh McLennan comply with GDPR ?
According to Rankiteo, Marsh McLennan is not listed as GDPR compliant.
Does Marsh McLennan have PCI DSS certification ?
According to Rankiteo, Marsh McLennan does not currently maintain PCI DSS compliance.
Does Marsh McLennan comply with HIPAA ?
According to Rankiteo, Marsh McLennan is not compliant with HIPAA regulations.
Does Marsh McLennan have ISO 27001 certification ?
According to Rankiteo,Marsh McLennan is not certified under ISO 27001, indicating the absence of a formally recognized information security management framework.
Industry Classification of Marsh McLennan
Marsh McLennan operates primarily in the Financial Services industry.
Number of Employees at Marsh McLennan
Marsh McLennan employs approximately 67,727 people worldwide.
Subsidiaries Owned by Marsh McLennan
Marsh McLennan presently has no subsidiaries across any sectors.
Marsh McLennan’s LinkedIn Followers
Marsh McLennan’s official LinkedIn profile has approximately 810,970 followers.
NAICS Classification of Marsh McLennan
Marsh McLennan is classified under the NAICS code 52, which corresponds to Finance and Insurance.
Marsh McLennan’s Presence on Crunchbase
No, Marsh McLennan does not have a profile on Crunchbase.
Marsh McLennan’s Presence on LinkedIn
Yes, Marsh McLennan maintains an official LinkedIn profile, which is actively utilized for branding and talent engagement, which can be accessed here: https://www.linkedin.com/company/marshmclennan.
Cybersecurity Incidents Involving Marsh McLennan
As of November 27, 2025, Rankiteo reports that Marsh McLennan has experienced 3 cybersecurity incidents.
Number of Peer and Competitor Companies
Marsh McLennan has an estimated 29,513 peer or competitor companies worldwide.
What types of cybersecurity incidents have occurred at Marsh McLennan ?
Incident Types: The types of cybersecurity incidents that have occurred include Data Leak and Breach.
How does Marsh McLennan detect and respond to cybersecurity incidents ?
Detection and Response: The company detects and responds to cybersecurity incidents through an containment measures with reset system access rights, containment measures with imposed additional restrictions..
Incident Details
Can you provide details on each incident ?
Title: Marsh & McLennan Data Breach
Description: Marsh & McLennan Cos. Inc. was hit by a data breach in April involving access to Social Security numbers and other personal information of staff, former staff, clients, and a range of other people linked to the brokerage.
Date Detected: April 2023
Type: Data Breach
Title: Marsh & McLennan Companies, Inc. Data Breach
Description: Unauthorized access to personal information, including names and Social Security Numbers, through Kroll Background Screening Services.
Date Detected: 2013-09
Date Publicly Disclosed: 2013-11-26
Type: Data Breach
Attack Vector: Unauthorized Access
Title: Marsh McLennan Data Breach
Description: Unauthorized access to personal information including names, Social Security numbers, driver's license numbers, and health insurance information.
Date Detected: 2021-04-26
Date Publicly Disclosed: 2021-06-30
Type: Data Breach
Attack Vector: Unauthorized Access
What are the most common types of attacks the company has faced ?
Common Attack Types: The most common types of attacks the company has faced is Breach.
Impact of the Incidents
What was the impact of each incident ?
Incident : Data Breach MAR18242223
Data Compromised: Social security numbers, Federal tax identification numbers, Names
Identity Theft Risk: True
Incident : Data Breach MAR307072525
Data Compromised: Names, Social security numbers
Incident : Data Breach MAR919072625
Data Compromised: Names, Social security numbers, Driver's license numbers, Health insurance information
What types of data are most commonly compromised in incidents ?
Commonly Compromised Data Types: The types of data most commonly compromised in incidents are Social Security Numbers, Federal Tax Identification Numbers, Names, , Names, Social Security Numbers, , Names, Social Security Numbers, Driver'S License Numbers, Health Insurance Information and .
Which entities were affected by each incident ?
Incident : Data Breach MAR18242223
Entity Name: Marsh & McLennan Cos. Inc.
Entity Type: Company
Industry: Brokerage
Incident : Data Breach MAR307072525
Entity Name: Marsh & McLennan Companies, Inc.
Entity Type: Corporation
Industry: Professional Services
Incident : Data Breach MAR919072625
Entity Name: Marsh McLennan
Entity Type: Company
Industry: Insurance
Customers Affected: 2550
Response to the Incidents
What measures were taken in response to each incident ?
Incident : Data Breach MAR18242223
Containment Measures: Reset system access rightsImposed additional restrictions
Data Breach Information
What type of data was compromised in each breach ?
Incident : Data Breach MAR18242223
Type of Data Compromised: Social security numbers, Federal tax identification numbers, Names
Sensitivity of Data: High
Incident : Data Breach MAR307072525
Type of Data Compromised: Names, Social security numbers
Sensitivity of Data: High
Incident : Data Breach MAR919072625
Type of Data Compromised: Names, Social security numbers, Driver's license numbers, Health insurance information
Number of Records Exposed: 2550
Sensitivity of Data: High
How does the company handle incidents involving personally identifiable information (PII) ?
Handling of PII Incidents: The company handles incidents involving personally identifiable information (PII) through by reset system access rights, imposed additional restrictions and .
References
Where can I find more information about each incident ?
Incident : Data Breach MAR18242223
Source: Marsh & McLennan Cos. Inc.
Incident : Data Breach MAR307072525
Source: California Office of the Attorney General
Date Accessed: 2013-11-26
Incident : Data Breach MAR919072625
Source: Washington State Office of the Attorney General
Where can stakeholders find additional resources on cybersecurity best practices ?
Additional Resources: Stakeholders can find additional resources on cybersecurity best practices at and Source: Marsh & McLennan Cos. Inc., and Source: California Office of the Attorney GeneralDate Accessed: 2013-11-26, and Source: Washington State Office of the Attorney General.
Stakeholder and Customer Advisories
Were there any advisories issued to stakeholders or customers for each incident ?
Incident : Data Breach MAR18242223
Customer Advisories: Complimentary credit monitoring for two yearsIdentity theft detection and resolution servicesUp to $1 million in identity theft insurance coverage
What advisories does the company provide to stakeholders and customers following an incident ?
Advisories Provided: The company provides the following advisories to stakeholders and customers following an incident: were Complimentary Credit Monitoring For Two Years, Identity Theft Detection And Resolution Services, Up To $1 Million In Identity Theft Insurance Coverage and .
Additional Questions
Incident Details
What was the most recent incident detected ?
Most Recent Incident Detected: The most recent incident detected was on April 2023.
What was the most recent incident publicly disclosed ?
Most Recent Incident Publicly Disclosed: The most recent incident publicly disclosed was on 2021-06-30.
Impact of the Incidents
What was the most significant data compromised in an incident ?
Most Significant Data Compromised: The most significant data compromised in an incident were Social Security numbers, Federal tax identification numbers, Names, , Names, Social Security Numbers, , names, Social Security numbers, driver's license numbers, health insurance information and .
Response to the Incidents
What containment measures were taken in the most recent incident ?
Containment Measures in Most Recent Incident: The containment measures taken in the most recent incident was Reset system access rightsImposed additional restrictions.
Data Breach Information
What was the most sensitive data compromised in a breach ?
Most Sensitive Data Compromised: The most sensitive data compromised in a breach were Federal tax identification numbers, Social Security numbers, Names, driver's license numbers, health insurance information, names and Social Security Numbers.
What was the number of records exposed in the most significant breach ?
Number of Records Exposed in Most Significant Breach: The number of records exposed in the most significant breach was 255.0.
References
What is the most recent source of information about an incident ?
Most Recent Source: The most recent source of information about an incident are Marsh & McLennan Cos. Inc., California Office of the Attorney General and Washington State Office of the Attorney General.
Stakeholder and Customer Advisories
What was the most recent customer advisory issued ?
Most Recent Customer Advisory: The most recent customer advisory issued was an Complimentary credit monitoring for two yearsIdentity theft detection and resolution servicesUp to $1 million in identity theft insurance coverage.
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Latest Global CVEs (Not Company-Specific)
Description
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to versions 19.2.16, 20.3.14, and 21.0.1, there is a XSRF token leakage via protocol-relative URLs in angular HTTP clients. The vulnerability is a Credential Leak by App Logic that leads to the unauthorized disclosure of the Cross-Site Request Forgery (XSRF) token to an attacker-controlled domain. Angular's HttpClient has a built-in XSRF protection mechanism that works by checking if a request URL starts with a protocol (http:// or https://) to determine if it is cross-origin. If the URL starts with protocol-relative URL (//), it is incorrectly treated as a same-origin request, and the XSRF token is automatically added to the X-XSRF-TOKEN header. This issue has been patched in versions 19.2.16, 20.3.14, and 21.0.1. A workaround for this issue involves avoiding using protocol-relative URLs (URLs starting with //) in HttpClient requests. All backend communication URLs should be hardcoded as relative paths (starting with a single /) or fully qualified, trusted absolute URLs.
Risk Information
cvss4
Base: 7.7
Severity: LOW
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
References
- https://github.com/angular/angular/commit/0276479e7d0e280e0f8d26fa567d3b7aa97a516f
- https://github.com/angular/angular/commit/05fe6686a97fa0bcd3cf157805b3612033f975bc
- https://github.com/angular/angular/commit/3240d856d942727372a705252f7c8c115394a41e
- https://github.com/angular/angular/releases/tag/19.2.16
- https://github.com/angular/angular/releases/tag/20.3.14
- https://github.com/angular/angular/releases/tag/21.0.1
- https://github.com/angular/angular/security/advisories/GHSA-58c5-g7wp-6w37
Description
Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. An Uncontrolled Recursion vulnerability in node-forge versions 1.3.1 and below enables remote, unauthenticated attackers to craft deep ASN.1 structures that trigger unbounded recursive parsing. This leads to a Denial-of-Service (DoS) via stack exhaustion when parsing untrusted DER inputs. This issue has been patched in version 1.3.2.
Risk Information
cvss4
Base: 8.7
Severity: LOW
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Description
Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. An Integer Overflow vulnerability in node-forge versions 1.3.1 and below enables remote, unauthenticated attackers to craft ASN.1 structures containing OIDs with oversized arcs. These arcs may be decoded as smaller, trusted OIDs due to 32-bit bitwise truncation, enabling the bypass of downstream OID-based security decisions. This issue has been patched in version 1.3.2.
Risk Information
cvss4
Base: 6.3
Severity: LOW
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Description
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. Prior to versions 7.0.13 and 8.0.2, working with large buffers in Lua scripts can lead to a stack overflow. Users of Lua rules and output scripts may be affected when working with large buffers. This includes a rule passing a large buffer to a Lua script. This issue has been patched in versions 7.0.13 and 8.0.2. A workaround for this issue involves disabling Lua rules and output scripts, or making sure limits, such as stream.depth.reassembly and HTTP response body limits (response-body-limit), are set to less than half the stack size.
Risk Information
cvss3
Base: 7.5
Severity: LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Description
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. In versions from 8.0.0 to before 8.0.2, a NULL dereference can occur when the entropy keyword is used in conjunction with base64_data. This issue has been patched in version 8.0.2. A workaround involves disabling rules that use entropy in conjunction with base64_data.
Risk Information
cvss3
Base: 7.5
Severity: LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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Incident
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Digital Assets
Every week, Rankiteo analyzes billions of signals to give organizations a sharper, faster view of emerging risks. With deeper, more actionable intelligence at their fingertips, security teams can outpace threat actors, respond instantly to Zero-Day attacks, and dramatically shrink their risk exposure window.
These are some of the factors we use to calculate the overall score:
Network Security
Identify exposed access points, detect misconfigured SSL certificates, and uncover vulnerabilities across the network infrastructure.
SBOM (Software Bill of Materials)
Gain visibility into the software components used within an organization to detect vulnerabilities, manage risk, and ensure supply chain security.
CMDB (Configuration Management Database)
Monitor and manage all IT assets and their configurations to ensure accurate, real-time visibility across the company's technology environment.
Threat Intelligence
Leverage real-time insights on active threats, malware campaigns, and emerging vulnerabilities to proactively defend against evolving cyberattacks.
Rankiteo is a unified scoring and risk platform that analyzes billions of signals weekly to help organizations gain faster, more actionable insights into emerging threats. Empowering teams to outpace adversaries and reduce exposure.
