CVE-2026-53904
CWE-307Published: July 1, 2026· Updated: Jul 1, 2026
Official Description
MCO is vulnerable to Account Denial of Service due to improper implementation of password reset functionality. Each password reset request invalidates previously set password as well as previously issued temporary passwords, furthermore, password resets are not limited in any way. An attacker who provides victim's email and answer to their security question, can successfully initiate the reset process and continuously invalidate credentials, effectively locking the victim out of their account. Answering security questions has a limited number of tries which lowers the risk of this vulnerability.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
Technical Analysis
CVE-2026-53904 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (2)
Quick Facts
Related CVEs (CWE-307)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-53904 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts