Affects widely used Exchange Online; privilege escalation could disrupt tenants across industries.
CVE-2026-48582
Exchange Online: missing authorization enables privilege escalation.
Is CVE-2026-48582 being exploited?
Not confirmed. CVE-2026-48582 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.69% probability of exploitation in the next 30 days.
How severe is CVE-2026-48582?
CVE-2026-48582 is rated Critical with a CVSS score of 9.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-48582?
Yes. A fix has been recorded for CVE-2026-48582. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-48582 affect?
CVE-2026-48582 affects Microsoft Exchange Online (Microsoft 365). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-48582?
Patch when released; audit privileges; restrict admin access.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Privilege escalation within Exchange Online tenant via missing authorization; attacker with network access can gain admin-like rights.
Patch when possible