Closing the year strong: SaaS security gaps you can’t carry into 2026

As 2025 draws to a close, IT and security leaders face a familiar yet increasingly urgent question: Are we truly protected against modern SaaS threats?

For many organizations, the answer is still “no.”

The rapid adoption of cloud collaboration platforms, such as Microsoft 365 and Google Workspace, coupled with third-party integrations and remote work, has expanded the attack surface beyond what traditional tools or built-in security features in these applications can manage.

The coming year demands a renewed focus on SaaS risk posture. Cyberthreats are becoming more dangerous than ever, with threat actors leveraging automation, AI and “as-a-service” attack models to exploit weaknesses in human behavior, misconfigurations and neglected cloud assets.

Read on to discover the top SaaS security gaps that your organization must close before 2026.

The expanding SaaS threat landscape

The modern SaaS ecosystem is now a primary focus for cybersecurity and is becoming more complex every day.

Unlike traditional on-premises environments, SaaS platforms are deeply interconnected, rely on user behavior and are dependent on constant configuration oversight. In a SaaS world, every login, app connection, shared file or granted permission can potentially open a new doorway for risk.

At the same time, cybercriminals continually upgrade their tactics. Modern cyberattack techniques, such as automated exploitation, AI-powered phishing and token-based hijacking, enable attackers to infiltrate corporate environments undetected.

It isn’t just the volume and severity of threats that keep IT and security leaders up at night. For most organizations, the primary challenge is a lack of visibility and the inability to respond quickly enough. Disconnected point solutions can’t keep up with SaaS-specific risks or provide the unified prevention, response and recovery functionality needed to stay ahead of today’s evolving SaaS threats.

The 10 critical SaaS security gaps you must close before 2026

As SaaS threats grow more complex and dangerous, even minor security blind spots can escalate into major incidents. Below are ten critical SaaS security gaps every IT and security team must address before entering 2026. Addressing them now will reduce exposure, improve response readiness and strengthen resilience in the year ahead.

Phishing

Phishing continues to be one of the most effective hacking methods in an attacker’s toolkit. Attackers craft realistic, deceptive messages to trick users into handing over SaaS credentials and divulging sensitive personal information. The 2026 Kaseya Cybersecurity Outlook report found that 56% of organizations have been affected to date, with almost half (49%) experiencing an attack in the past year alone.

Today, even low-skilled cybercriminals can rent ready-to-use phishing kits through Phishing-as-a-Service (PhaaS) platforms. These offerings have made large-scale phishing attacks cheap, fast and significantly easier to execute.

How to defend against it

• Train users to recognize and avoid phishing attempts through continuous education.
• Combine training and awareness with preventative tools that automatically respond to suspicious behavior.
• Leverage automation to stop phishing attempts before they lead to data breaches or credential theft.
• Reinforce user readiness by hosting mandatory webinars, running lunch-and-learn sessions or conducting simulated phishing attacks.

Token hijacking

Token hijacking is quickly becoming one of the most dangerous threats in today’s SaaS-driven business landscape. Unlike brute-force attacks, which rely on guessing passwords, token hijacking involves stealing session tokens or the digital keys that allow threat actors to bypass passwords entirely.

Once attackers obtain active authentication tokens, they can compromise accounts, move laterally and extract sensitive data without ever triggering a password prompt. Token hijacking is faster, stealthier and far more effective than traditional account-based attacks, making it an increasingly popular strategy among cybercriminals.

How to defend against it

• Strengthen anti-phishing defenses. Train users to identify suspicious emails and spoofed domains and verify login links before entering credentials to reduce the chances of tokens being intercepted.
• Monitor accounts continuously to detect and block access when unusual login behavior is detected.
• Leverage cutting-edge security tools that automatically detect threats and shut down unauthorized access before attackers can inflict additional damage.

IP address localization/IP spoofing

Remote work increases the importance of IP tracking for SaaS security because attackers often hide their true locations. They use advanced strategies, such as IP spoofing, VPNs and proxy servers, to conceal their identity and evade detection, making attacks more difficult to trace.

How to defend against it

• Make continuous login monitoring a priority. Regularly track account activity and flag unusual or unexpected login patterns.
• Use advanced monitoring tools to identify suspicious behavior that extends beyond basic location checks.
• Automate your security responses. Configure automated actions to block unauthorized logins and immediately alert IT teams when anomalies occur.
• Watch for additional red flags. Even if a login appears legitimate, attackers using IP localization may reveal themselves through unusual file activity, such as unexpected modifications, downloads or uploads.
• Minimize whitelisted locations. Reduce exposure by limiting access to specific IP addresses or small, tightly controlled IP ranges whenever possible.

Risky file-sharing behavior

SaaS collaboration tools make sharing effortless, but they also increase the risk of accidentally exposing confidential business data. Employees may unknowingly share sensitive documents with external collaborators or even make files publicly accessible without realizing the implications.

And it happens more often than you might think. In 2024, SaaS Alerts detected more than 15,787 files being shared every hour. While most of these exchanges were internal, nearly 40% of those events occurred outside the organization, increasing the risk of data leaks, compliance violations and security breaches.

How to defend against it

• Monitor file-sharing activity to ensure users aren’t unknowingly exposing sensitive data.
• Regularly remove old or orphaned sharing links to close hidden security gaps.
• Educate employees on secure sharing practices to reduce the risk of accidental data leaks.

Orphaned file-sharing links

Microsoft 365 and Google Workspace are by far the most frequently used platforms for sharing and distributing data. However, this convenience comes with a significant security risk: orphaned file-sharing links that remain active long after they should have been revoked.

These orphaned file-sharing links create a silent backdoor for cybercriminals. Even if the original user no longer needs to share the file, the link often remains active indefinitely, allowing unauthorized users to access sensitive data with a single click.

In many cases, the risk isn’t intentional sharing; it’s forgotten sharing, which leaves confidential information exposed for months or even years. These “orphaned” links are prime targets for attackers searching for easy, low-friction entry points.

The numbers show how widespread the problem is:

Microsoft 365: 37,105,124 files (44.7%) were shared externally in 2024.

Google Workspace: 14,440,407 files (26.1%) were shared externally in the same year.

With millions of files leaving the safety of the organization, even a small percentage of orphaned links represents a significant security threat.

How to defend against it

• Set expiration dates for all shared links to ensure access automatically ends when it’s no longer needed.
• Restrict sharing permissions to specific users rather than allowing broad or public access.
• Establish regular audits of shared content to identify and remove outdated or unnecessary links.
• Disable editing or downloading on view-only files to prevent recipients from redistributing content beyond the intended scope.

Insider threats

Insider threats are security risks that originate from within an organization. Whether intentional or unintentional, insider threats remain one of the hardest risks to detect. It can be a disgruntled employee downloading customer data for personal or financial gain, or a well-meaning but careless employee accidentally deleting data, mishandling sensitive information or falling for social engineering scams.

How to defend against it

• Implement strong access controls, including the principle of least privilege.
• Continuously monitor user activity to catch suspicious behavior early.
• Conduct regular security training to reinforce safe practices and reduce risky actions.
• Back up and protect your SaaS data to ensure continuity in the event of an insider incident.
• Develop a robust incident response plan to quickly contain and mitigate potential damage.

Business email compromise

Business email compromise (BEC) is a form of social engineering attack in which cybercriminals impersonate trusted figures, such as executives, vendors or partners, to trick employees into transferring funds or divulging confidential business information. These attacks often rely on creating a false sense of urgency, pressuring victims to act quickly before they have a chance to verify the legitimacy of the request.

How to defend against it

• Use MFA wherever possible to add an extra layer of authentication for all account access.
• Deploy advanced email security solutions that leverage AI and behavioral analysis to detect impersonation attempts.
• Keep all software up to date to reduce exploitable vulnerabilities.
• Implement strict verification procedures for all financial transactions, especially large wire transfers or changes to payment details.
• Conduct regular security awareness training to help employees recognize common BEC red flags such as urgency, secrecy and mismatched “reply-to” addresses.
• Simulate phishing attacks to reinforce training and measure user resilience.

Forgotten or unmonitored guest user accounts

Guest user accounts, such as those created for contractors, vendors or partners, can pose a significant security risk if they are forgotten or not regularly reviewed, updated or removed. Unfortunately, guest access in Microsoft 365 and Google Workspace often persists long after a project ends.

According to the SaaS Application Security Insights 2025 (SASI) report, of the 4,261,624 SaaS accounts monitored by SaaS Alerts in 2024, more than half (55.24%) were guest user accounts rather than licensed users.

How to manage guest accounts

• Apply time-bound access policies to enforce automatic expiration for guest accounts.
• Review and remove unused accounts regularly (at least once a month).
• Block sign-in for accounts whose necessity is unclear rather than leaving them active.
• Automate guest account cleanup to reduce manual oversight and minimize risk.

Lack of MFA enforcement

MFA is one of the most effective defenses against account takeovers, yet it remains one of the most inconsistently applied. Many organizations enable MFA for some users but overlook privileged accounts, service accounts or legacy integrations, leaving critical gaps in their security posture.

As per the SASI report, more than 60% of end-user accounts still have MFA turned off or inactive. That means more than half of users rely solely on passwords at a time when cybercriminals are more sophisticated than ever. Without consistent MFA enforcement, even a single compromised credential can give threat actors unrestricted access to business-critical data and systems.

What you should do

• Mandate MFA for every user. Use SaaS monitoring tools to see exactly which users have MFA turned off and fix it quickly.
• Implement advanced cloud detection and response tools to instantly block risky sign-ins, expire active sessions or force MFA at the next login.

SaaS-to-SaaS app integrations

OAuth-based logins have made it easier than ever for users to connect new SaaS tools, but they’ve also created one of today’s most overlooked security risks. Every time someone clicks “Sign in with Microsoft” or “Connect to Google,” a new integration is created. If no one is monitoring these connections, they can spread through your environment unchecked. One risky integration is all it takes to expose sensitive business data.

What you should do

• Continuously monitor all OAuth logins/enterprise applications and extend security beyond just Google and Microsoft applications.
• Keep a close watch on app-to-app integrations to prevent unintended security gaps.
• Leverage advanced SaaS security tools that provide real-time tracking and alerts for OAuth logins, enabling IT teams to detect unauthorized activity, identify patterns and prevent potential breaches efficiently.

The Kaseya 365 User advantage

Kaseya 365 User was designed to make SaaS security comprehensive, automated and scalable. Rather than juggling multiple point solutions, IT teams gain access to essential security components in a single subscription.

Here’s how Kaseya 365 User covers the full SaaS security lifecycle:

Prevent

• Email security to block threats at the inbox.
• User awareness training and susceptibility testing to strengthen human resilience.
• Dark web monitoring to identify exposed credentials before attackers exploit them.

Respond

• Cloud detection and response with full visibility into SaaS security events.
• Real-time alerting and automated remediation, such as account locking or terminating dangerous end-user file sharing, for rapid containment.
• Apply Microsoft security recommendations across all your accounts in minutes.
• Strengthen user identity validation and cyber protection by linking your users’ SaaS applications to their managed devices, providing an extra layer of security.

Recover

• SaaS backup and recovery ensures fast, reliable data restoration across Microsoft 365 and Google Workspace.
• Protects against accidental deletion, ransomware and malicious insider actions.

Kaseya 365 User includes a common core set of integrations and more than 50 automations, enabling IT teams to achieve substantial time savings, workflow efficiency and operational scalability, all without adding complexity.

Start 2026 with confidence with Kaseya 365 User

As you plan for 2026, the question isn’t whether you’ll face a SaaS-based incident, but how prepared you’ll be when it happens.

By closing these ten critical gaps and adopting a proactive, layered defense approach, your organization can strengthen its resilience and ensure continuity in the event of an unforeseen incident.

Don’t let 2025’s vulnerabilities follow you into 2026. Discover how Kaseya 365 User can help close the blind spots and reinforce your SaaS security foundation. Learn more.