CVE-2026-48582
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedMissing authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceMissing authorization vulnerability in Microsoft Exchange Online enables an authenticated attacker to escalate privileges beyond their assigned permissions. This broken access control flaw allows network-based privilege elevation, potentially granting unauthorized access to higher-privilege mailboxes or administrative functions.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm Exchange Online usageUse the Microsoft 365 admin center (admin.microsoft.com) or run Get-OrganizationConfig in Exchange Online PowerShell to verify your organization uses Exchange Online servicesAffected if Your organization uses Microsoft Exchange Online for email services
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Identify privileged role assignmentsRun Get-RoleGroupMember in Exchange Online PowerShell to list members of privileged role groups (e.g., Organization Management, Recipient Management, Help Desk)Affected if Users exist in privileged role groups beyond their legitimate job functions
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Review non-privileged user permissionsRun Get-MailboxPermission for sample mailboxes to check if standard users have unexpected Send-As, Full-Access, or mailbox delegation permissionsAffected if Non-administrative users have elevated mailbox permissions they should not possess
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Check for excessive Role Group membershipsRun Get-User in Exchange Online PowerShell for administrative accounts and review their AssignedRoles and RoleGroupMembershipsAffected if Users have been assigned roles outside their intended permission scope
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Examine audit logs for privilege changesSearch unified audit log in Microsoft 365 compliance center for events like 'Add member to role' or 'Update role group' performed by standard usersAffected if Audit logs show unauthorized privilege escalation attempts or role modifications
Your organization is affected if it uses Microsoft Exchange Online and has any users with permissions beyond their assigned RBAC scope, or if audit logs show unauthorized privilege escalation activity.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedApply Microsoft security updates for Exchange Online when available; review and enforce role-based access control (RBAC) assignments and conditional access policies to limit privilege escalation paths.
- This vulnerability affects Microsoft Exchange Online, which is a cloud-managed service.
- Customers cannot directly upgrade, patch, or configure Exchange Online themselves.
- Microsoft manages the Exchange Online infrastructure and is responsible for applying security fixes.
- Monitor the Microsoft 365 admin center and Microsoft Security Response Center (msrc.microsoft.com) for updates on when the fix has been applied.
- Review Microsoft Purview compliance portal for any recommended security configurations that may help mitigate privilege escalation risks while waiting for the fix.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,888.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-48582 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-48582 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data