Vulnerability · Published Jun 4, 2026 · Assigned by microsoft
CVE-2026-48579Microsoft Exchange Online Information Disclosure Vulnerability
Critical 9.1
In plain English
A critical-severity security flaw in Microsoft Exchange Online from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 63% of all known vulnerabilities).
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)1.0%top 36.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Improper authorization in Microsoft Exchange Online allows an unauthorized attacker to disclose information over a network.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft Exchange Online | - |
Weakness: CWE-285 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C
References
- Microsoft Exchange Online Information Disclosure Vulnerability vendor-advisory, patch