Cyber Brief: London council incidents and third party risks

Yesterday saw two developments with direct implications for UK organisations. Multiple London councils reported cyber disruption affecting public services, while a newly disclosed breach overseas highlighted the ongoing risks created by third party providers. Both incidents reinforce a familiar message: attackers continue to target the weakest points in increasingly interconnected environments.

London councils face disruption following cyber incidents

Several London borough councils reported cyber incidents that affected shared IT services and public facing operations. In some cases, access to online platforms, phone systems and internal tools had to be restricted while teams worked to contain the issue. Although details on the nature of the attacks remain limited, early indications suggest that shared infrastructure used across multiple councils may have been targeted.
Incidents like these reflect the challenges faced by public sector organisations that rely on centralised or shared IT functions. While this model improves efficiency, it also creates concentrated points of failure if controls are not aligned across all participating councils. Recovery efforts often require coordination across multiple teams, suppliers and service partners, which can slow down incident response and impact service delivery.

Why it matters
Local authorities handle sensitive personal data and operate essential services. A disruption affecting shared systems can have a cascading effect across multiple boroughs. Organisations with shared infrastructure models should validate segmentation controls, ensure independent logging and monitoring are in place and test incident response plans that involve external partners.

Source
Computer Weekly

New third party breach highlights ongoing supplier exposure

A recently disclosed data breach involving a large financial services technology provider has reinforced the persistent risk of relying on third party vendors. In this case, unauthorised access to internal systems led to the exposure of records relating to multiple client organisations. Although the provider has begun notifying affected customers, investigations are ongoing and the full scope is not yet known.
The incident serves as another reminder that even well established service providers remain attractive targets for threat actors. Attackers continue to exploit supplier networks because compromising one vendor can provide access to many downstream organisations. As digital supply chains expand, maintaining oversight of third party security controls has become increasingly challenging, particularly when providers operate complex or interconnected environments.

Why it matters
Third party compromise remains one of the most common breach pathways. Organisations should ensure suppliers meet minimum security requirements, undergo regular assessments and support transparent incident reporting. Strong contractual expectations, continuous monitoring and rapid communication channels are essential to reduce the impact of supplier related incidents.

Source
Computer Weekly

Today’s Key Actions

1. Validate segmentation and monitoring across any shared or multi tenant infrastructure.
2. Review supplier exposure, focusing on high impact third parties with access to sensitive systems.
3. Ensure contracts define clear incident reporting obligations and communication timelines.
4. Test incident response plans involving external partners and coordinated recovery.
5. Refresh risk registers to reflect supplier and shared service dependencies.

Secarma Insight

The incidents from yesterday reinforce a simple truth: cyber resilience depends on the strength of your ecosystem. Shared services and third party providers deliver efficiency, but they also introduce blind spots when assurance is inconsistent. Organisations that prioritise supplier governance, shared infrastructure visibility and coordinated response planning will be better placed to prevent small weaknesses from becoming large scale disruptions.

Get in touch with us to prioritise your next steps and strengthen your security posture.