Jul 2026: Microsoft Exchange Online Tampering Vulnerability
CVE-2026-56191 Published on July 24, 2026
Microsoft Exchange Online Tampering Vulnerability
Improper authentication in Microsoft Exchange Online allows an unauthorized attacker to perform tampering over a network.
Weakness Type
What is an authentification Vulnerability?
When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.
CVE-2026-56191 has been classified to as an authentification vulnerability or weakness.
Products Associated with CVE-2026-56191
Want to know whenever a new CVE is published for Microsoft Exchange Online? stack.watch will email you.
Affected Versions
Microsoft Exchange Online Version - is affected by CVE-2026-56191Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.