CVE-2026-62882 in Office 365 Apps for Enterprise
Summary
by MITRE • 08/11/2026
Insufficiently protected credentials in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical weakness in Microsoft Office Outlook's credential protection mechanisms that enables unauthorized attackers to conduct spoofing attacks over network communications. The flaw stems from inadequate safeguards around authentication tokens and session management within the email client, creating opportunities for malicious actors to impersonate legitimate users and gain access to sensitive email accounts. The vulnerability specifically affects how Outlook handles credential storage and transmission during network-based operations, particularly when communicating with Exchange servers or other email infrastructure components.
The technical implementation of this weakness allows attackers to intercept, manipulate, or reuse authentication credentials without proper validation mechanisms. This typically occurs when Outlook fails to adequately encrypt or protect sensitive authentication data during network transmission, or when the client does not properly verify the authenticity of server responses before establishing trusted connections. The vulnerability can be exploited through various attack vectors including man-in-the-middle scenarios, credential harvesting techniques, or by leveraging weak cryptographic implementations in the email client's communication protocols. Security researchers have identified that this flaw particularly impacts Outlook versions that rely on older authentication methods or fail to implement proper mutual authentication between client and server components.
The operational impact of this vulnerability extends beyond simple credential theft to encompass broader security compromise scenarios where attackers can conduct persistent surveillance, execute unauthorized email operations, and potentially escalate privileges within organizational email infrastructures. When successful, spoofing attacks enabled by this weakness allow adversaries to send emails that appear to originate from legitimate users, enabling social engineering campaigns, phishing attacks, and data exfiltration efforts. Organizations may experience significant reputational damage, regulatory compliance violations, and financial losses due to the unauthorized access capabilities this vulnerability provides. The risk is particularly elevated in enterprise environments where Outlook serves as the primary email client and where users frequently access corporate mailboxes through network connections.
Mitigation strategies should focus on implementing comprehensive credential protection measures including mandatory encryption of all email communications, enforcement of strong authentication protocols such as OAuth 2.0 or modern authentication methods, and regular security updates to address known vulnerabilities in Outlook implementations. Organizations must ensure proper configuration of certificate validation mechanisms and implement network monitoring solutions that can detect anomalous authentication patterns or unauthorized access attempts. Security controls should also include mandatory multi-factor authentication for email access, regular credential rotation policies, and network segmentation to limit the attack surface available to potential adversaries. Additionally, administrators should conduct regular security assessments to identify and remediate any outdated authentication methods that may expose systems to this type of credential exposure vulnerability. This issue aligns with CWE-521 Weak Password Requirements and ATT&CK technique T1566 Phishing, highlighting the need for comprehensive email security controls that address both client-side vulnerabilities and network-level protections against credential compromise attacks.