For many, password managers have become essential tools for navigating the increasingly complex digital landscape. With an estimated 94 million US adults – roughly 36 percent of the population – now relying on these services, they store not just passwords for email and banking, but also sensitive data like cryptocurrency credentials and credit card numbers. But a core promise underpinning the widespread adoption of these tools – that your data is completely secure, even from the service provider itself – is now under scrutiny.
The security proposition of password managers hinges on what’s known as “zero knowledge” encryption. Eight leading providers tout this feature, assuring users that even if their servers are compromised, or malicious insiders attempt to access data, the contents of their vaults remain protected. This assurance is particularly relevant given recent high-profile breaches, such as the one experienced by LastPass and the understanding that sophisticated actors may target individuals with valuable online accounts.
However, novel research suggests that the “zero knowledge” claim isn’t universally true. Security researchers have identified vulnerabilities in popular password managers – including Bitwarden, Dashlane, and LastPass, collectively used by approximately 60 million people – that could allow access to user data under certain circumstances. These vulnerabilities arise particularly when account recovery features are enabled, or when users share vaults or collaborate within groups.
Bitwarden, Dashlane, and LastPass have all publicly stated their commitment to protecting user data. Bitwarden claims “not even the team at Bitwarden can read your data (even if we wanted to).” Dashlane asserts that without a user’s master password, “malicious actors can’t steal the information, even if Dashlane’s servers are compromised.” LastPass states that no one can access the “data stored in your LastPass vault, except you (not even LastPass).” But the recent analysis reveals potential weaknesses in these protections.
How ‘Zero Knowledge’ Can Be Compromised
The research, which involved reverse-engineering and close analysis of the three password managers, uncovered methods for gaining access to data when administrative control of the server is compromised. In some cases, researchers were able to devise attacks that weakened encryption, potentially allowing ciphertext to be converted into readable plaintext. In other words that someone with sufficient access could, in theory, steal entire vaults or specific pieces of information.
The vulnerabilities aren’t necessarily due to flaws in the core encryption algorithms themselves, but rather in the implementation of features like account recovery, and sharing. Account recovery, although convenient for users who forget their master passwords, often requires storing some form of recoverable information, which can create a potential attack vector. Similarly, shared vaults and group access introduce complexities that can weaken overall security.
These findings raise concerns about the level of trust users place in password managers. While the risk of a widespread compromise remains relatively low, the potential for targeted attacks against high-value individuals or organizations is significant. The researchers emphasize that these vulnerabilities highlight the importance of understanding the limitations of even the most secure systems.
What This Means for Password Manager Users
The implications of these findings are significant for the millions who rely on password managers. While abandoning these tools entirely isn’t necessarily the answer – using strong, unique passwords remains crucial for online security – users should be aware of the potential risks and take steps to mitigate them.
One key recommendation is to carefully consider whether account recovery features are truly necessary. If you have a robust system for remembering your master password, disabling account recovery can significantly reduce your attack surface. Similarly, limiting the use of shared vaults and group access can enhance security.
Choosing a password manager is also critical. PCMag’s 2026 review of password managers highlights several options with strong security features and a commitment to user privacy. It’s important to research and select a provider that prioritizes security and transparency.
The ongoing debate around password manager security also underscores a broader trend: the need for greater scrutiny of “zero knowledge” claims. As more services adopt this approach, it’s essential that independent researchers and security experts continue to evaluate their implementations and identify potential vulnerabilities. A recent survey by PasswordManager.com found that 2 in 3 Americans still use predictable password patterns in 2026, highlighting the need for continued education and awareness.
Looking Ahead
The vulnerabilities identified in these password managers are likely to prompt a renewed focus on security best practices within the industry. Expect to observe providers strengthening their encryption protocols, refining account recovery mechanisms, and improving transparency around their security implementations. The National Cybersecurity Alliance offers online safety tips for older adults, but these are applicable to all users. The future of password management will likely involve a greater emphasis on user control and a more nuanced understanding of the trade-offs between security and convenience.
What are your thoughts on the security of password managers? Share your experiences and concerns in the comments below. And please, share this article with anyone you know who relies on a password manager to help them stay informed.
