What CISOs Must Prioritise in Mobile App Security in 2026

For a lot of organisations, the mobile app has become the main front door. It’s where customers log in, approve payments, sign things, and access the most sensitive data you have. If something breaks - or gets abused - it usually shows up in mobile first.

Attackers know that too. We’re seeing more industrialised mobile banking malware, more large-scale abuse of APIs built for mobile, more targeted credential attacks, and more risk coming from third-party SDKs. And because so much “mobile” actually runs in the cloud, a single misconfiguration behind the app can undermine the whole channel. At the same time, NIS2 and DORA are raising expectations for ICT risk management, incident reporting, and third-party oversight.

So the challenge for CISOs in 2026 isn’t awareness. It’s picking the priorities that actually reduce risk. Here are five that matter.

Crypto-Agility In The Mobile Channel

Cryptography underpins almost everything the mobile app does: login, authorisation, secure messaging, payment approvals, digital signatures and more. If algorithms, key sizes or certificate rules need to change and the organisation cannot move quickly, the mobile channel is where outages, fraud and reputational damage will show up first. That makes crypto-agility a board-level issue, not a niche engineering concern.

For CISOs, the priority is to be able to change cryptography across the whole mobile stack without breaking it. That requires a central cryptographic control point that defines which algorithms and key sizes are acceptable, and how keys and tokens are issued, rotated and revoked. Without that, any change in standards or the discovery of a cryptographic weakness turns into a major operational and security risk for the mobile channel.

Practical Actions:

• Build and maintain an inventory of cryptographic dependencies across mobile apps, SDKs and backends.
• Establish and enforce a central crypto policy for algorithms, key sizes and certificate profiles across mobile and backend services.
• Prepare and test an emergency key and certificate rotation playbook specifically for the mobile channel.

Using AI For Defence & Detecting AI-Driven Fraud

AI is already part of the mobile stack. On the defensive side, models assess device risk, session risk and transaction anomalies. On the offensive side, AI tools make phishing, fake support interactions and social engineering against mobile users far more convincing.

For CISOs focused on mobile, the AI priority is not “add more AI”. It is:

• Ensure relevant mobile telemetry feeds fraud and security models.
• Protect model and decision APIs exposed to mobile apps with strong authentication and authorisation.
• Detect AI-generated fraud attempts by watching for patterns that do not match normal human behaviour.

AI is a priority because it changes both the effectiveness of fraud and the organisation’s ability to detect it. If AI is not governed and secured in the mobile channel, it will quickly become an advantage for attackers rather than defenders.

Practical Actions:

• Protect model and decision APIs exposed to mobile apps with strong authentication, authorisation and rate-limiting, including per-client controls.
• Introduce adversarial testing for models and decision flows that drive high-value mobile actions such as payments, changes to payees and digital signatures.
• Ensure device, session, behavioural and fraud outcome telemetry from mobile is reliably fed into security and fraud models through a governed data pipeline.

Zero Trust For Mobile Users, Devices & APIs

Mobile apps run on devices the organisation does not own, on networks it does not control, often in high-risk contexts. Assuming that a device, session or network can be trusted because the user logged in once is no longer defensible. Applying zero-trust principles to mobile is therefore a core CISO responsibility.

This means:

• Binding accounts to devices and checking the device and app for signs of tampering where possible.
• Continuously assessing session and transaction risk, not just trusting a one-off login.
• Enforcing access rules at the API level, so every important API call from the app is checked, not just the first one.

Mobile apps then become strongly authenticated clients inside a wider zero-trust architecture.

Practical Actions:

• Implement strong device binding and, where feasible, app attestation for high-risk mobile transactions.
• Design step-up authentication journeys based on transaction value, behaviour and contextual risk signals.
• Require per-call authorisation for sensitive APIs, aligned with zero-trust policies for users, devices and services.

Cloud Security For Mobile Backends

On the user’s phone, the app is mainly a user interface. Business logic, data, identity, signing and authorisation happens on backend systems, often spread across several cloud platforms.

For CISOs, this means that mobile app security is largely determined by how well those cloud backends are controlled. This needs to be a priority because a weakness in one backend service can undermine the entire mobile channel.

Many organisations are moving towards a model where a single hardened service manages keys, tokens and cryptographic operations for mobile apps and their backends. That reduces the chance that one exposed key in one app becomes the entry point to core systems. For a CISO, bringing those backends under consistent cloud-security and crypto control is essential if the mobile app is to be trusted as a primary channel.

Practical Actions:

• Centralise secrets management for mobile apps and backends, using hardened key management and hardware-backed protection where possible.
• Use workload identities for services handling mobile traffic, avoiding long-lived shared secrets and embedded credentials.
• Apply least-privilege access and network segmentation between mobile-facing services and core banking or identity systems.
• Regularly review and harden cloud configurations for services and APIs exposed to mobile apps.

Compliance & Regulation

Regulatory demands on security, privacy and resilience in frameworks like GDPR, NIS2, DORA and PSD2 are increasingly tested through the mobile channel, so this cannot sit low on the roadmap.

If consent screens, permissions and tracking in the app do not match what privacy notices promise, or third-party SDKs send data in ways the organisation has not agreed, regulators will treat that as a failure of control, not a minor bug.

If strong customer authentication, transaction signing and audit logging are weak or poorly governed, it becomes harder to defend fraud disputes, prove compliance or demonstrate resilience after an incident.

That is why the mobile app and its backends should be treated as a regulated trust surface, with keys, certificates and signing operations managed and evidenced well enough to withstand audits, investigations and supervisory scrutiny.

Practical Actions:

• Put formal governance around third-party SDKs, including data-sharing assessments, contracts and ongoing behaviour review.
• Ensure cryptographic keys, certificates and signing operations generate evidence and audit trails that map to regulatory requirements for authentication, authorisation and non-repudiation.
• Build and rehearse mobile-specific incident reporting and customer communication playbooks that align with GDPR, NIS2, DORA and PSD2 timelines and expectations.

Framing Your 2026 Mobile App Security Strategy

For CISOs and security leaders, these five priorities give a practical way to frame mobile app security in 2026:

• Crypto-agility so that changes in standards or threats can be handled without chaos.
• AI used to defend the mobile channel, while detecting AI-driven fraud.
• Zero trust applied to mobile users, devices and APIs.
• Cloud security focused on the backends that mobile apps actually depend on.
• Compliance and regulation delivered through the app’s real behaviour, backed by strong cryptography.

Organisations that treat their mobile app as a critical, high-trust channel are increasingly investing in these areas, supported by centralised key management, robust cryptographic services and dedicated mobile app protection.