Vendor evidence profile
Microsoft Defender for Office 365: what the public record shows
nexalign keeps a continuously updated evidence record on Microsoft Defender for Office 365 for email security decisions: 35 items from 4 kinds of source, covering August 2025 to July 2026. Every item on this page links to the source it came from, carrying the date that source states and saying so plainly where it states none.
In one line
This record holds 3 advisories attributed to Microsoft Defender for Office 365 products across 35 evidence items in total, none of them in the CISA catalogue of known exploited vulnerabilities. 100 percent of the record comes from sources Microsoft Defender for Office 365 cannot edit. Whether Microsoft Defender for Office 365 suits your decision is not on this page: that depends on your criteria, your compliance scope and your shortlist, and this record does not know them.
Evidence items
35
in this record
Attributed advisories
3
none known exploited
Authoritative share
77%
government registers
Last checked
Jul 18, 2026
sources re-queried
How independent is this record
Sources are not equal. A vendor can rewrite its own website overnight and optimise it for whatever a language model is likely to quote. It cannot edit a government vulnerability register or a years-old discussion thread. Every item in this record is classified by how much the vendor could influence it, and the score below is the weighted result.
Independence of this record
Objectivity score 91/100
- Authoritative
- 27 items, 77 percent
- Independent
- 8 items, 23 percent
- Vendor-controlled
- 0 items, 0 percent
100 percent of this record comes from sources Microsoft Defender for Office 365 does not control. The remainder is Microsoft Defender for Office 365's own material and is marked as such wherever it appears.
Where this record comes from
These are the sources that contributed to the Microsoft Defender for Office 365 record, with the body that operates each one. No rating, score or ranking is taken from anywhere, and no vendor pays to appear in this index or to change what it says.
| Source | Operated by | Classification | Items | Latest |
|---|---|---|---|---|
| CERT-Bund security advisories | BSI, Federal Republic of Germany | Authoritative | 27 | Jul 15, 2026 |
| Analyst, review and reference sources | Recognised analysts, review marketplaces and technology press | Independent | 6 | Jul 18, 2026 |
| Engineering discussions | Hacker News, public threads | Independent | 1 | Aug 17, 2025 |
| Practitioner discussions | Reddit, public threads | Independent | 1 | Jan 22, 2026 |
Documented vulnerabilities
Vulnerability registers are searched by keyword, so an advisory about a different product often mentions Microsoft Defender for Office 365 in passing. An entry is only listed here when a structural signal ties it to a product of Microsoft Defender for Office 365: an advisory reference on the vendor's own domain, Microsoft Defender for Office 365 as the assigning authority, or the affected product list naming it. 3 records passed that test.
- WID-SEC-2026-2322mediumCVSS 7.8Jul 15, 2026
Affected products: Microsoft Defender, Microsoft Malware Protection Engine
- WID-SEC-2026-1848mediumCVSS 5.5Jun 10, 2026
Affected products: Microsoft Defender
- WID-SEC-2026-1603highCVSS 8.1May 21, 2026
Affected products: Microsoft Defender, Microsoft Malware Protection Engine
What practitioners report
Public threads in which engineers and administrators discuss running this product. Only threads naming Microsoft Defender for Office 365 in their own title are listed, so a discussion about someone else's incident cannot end up under this vendor. Not curated for sentiment: 0 threads in the record, most recent first.
The source ledger counts 2 further threads on these platforms that mention Microsoft Defender for Office 365 somewhere in the discussion without naming it in the title. They are searched and counted, and they are not listed as reports about this vendor.
Independent coverage
Recognised analysts, review marketplaces and neutral technology press that name Microsoft Defender for Office 365. This section runs on a fixed list of such outlets rather than on whatever a web search returns for the company name, because that search is dominated by sales-intelligence profiles and directory listings which say nothing about the product. Social networks and press-release wires are excluded outright.
- peerspot.comdate not recordedIndependent
Microsoft Defender for Office 365 vs Mimecast Advanced Email Security (2026)
- peerspot.comdate not recordedIndependent
Microsoft Defender for Office 365 Reviews, Competitors and Pricing
- gartner.comdate not recordedIndependent
Microsoft Defender for Office 365 Reviews & Ratings 2026 | Gartner Peer Insights
- peerspot.comdate not recordedIndependent
What is your primary use case for Microsoft Defender for Office 365?
- gartner.comdate not recordedIndependent
Microsoft Defender for Office 365 Reviews & Ratings 2026 | Gartner Peer Insights
What Microsoft Defender for Office 365 publishes about itself
The vendor's own documentation, kept separate from everything above and marked as vendor-controlled. It is useful, and it is a claim until an independent source confirms it.
What this record cannot tell you
A record is only trustworthy if it is explicit about its holes. These are the ones in the Microsoft Defender for Office 365 record right now.
A further 24 register entries mention Microsoft Defender for Office 365 without naming a product of Microsoft Defender for Office 365 as affected. They are excluded rather than counted as vulnerabilities.
No public practitioner discussion naming Microsoft Defender for Office 365 was found in the indexed threads. Operational experience with this product is not represented in this record.
Pricing, contract terms, notice periods and support commitments are not part of any public register. They come from the vendor and belong in a negotiation record.
Certification status such as ISO 27001, SOC 2 or BSI C5 has to be checked against the current certificate and its stated scope. A valid certificate can still exclude the product being bought.
Whether Microsoft Defender for Office 365 is the right choice is not on this page
A record of what is true about a vendor is one half of a decision. The other half is your context: which criteria matter, how heavily each one weighs, what is a hard no, and who has to sign the result off. No public page can know that, and any page that claims to rank vendors for you is guessing at it.
Typical criteria for this category
Needs your case- Detection Accuracy (MITRE ATT&CK coverage)weight
- MDR / Managed Detection & Responseweight
- Deployment Complexityweight
- Automated Response / Remediationweight
- SIEM Integrationweight
Criteria shown as examples for email security. Weighting and fit are properties of your decision, not of the vendor, so they are not published here.
What DecisionOS adds on top of this record
- The vendor scored against your criteria with your weighting, not against a generic ranking
- A dealbreaker check against your hard constraints: data residency, contract terms, existing stack
- A side-by-side view of the alternatives on your shortlist, built from this same evidence pool
- This evidence mapped onto your compliance scope: NIS2, DORA, ISO 27001, SOC 2
- A decision memo your board can read, with the trade-offs and the reasoning on the record
Questions this page answers
Is Microsoft Defender for Office 365 a safe choice?
The public record holds 3 advisories attributed to Microsoft Defender for Office 365 products and 35 evidence items in total. None of them appears in the CISA catalogue of known exploited vulnerabilities. Whether that is acceptable depends on your risk appetite, your compliance scope and the alternatives on your shortlist, none of which a public page can know. This page reports the record; it does not rate the vendor.
Where does the Microsoft Defender for Office 365 data on this page come from?
From 4 kinds of source: CERT-Bund security advisories, operated by BSI, Federal Republic of Germany; Analyst, review and reference sources, operated by Recognised analysts, review marketplaces and technology press; Engineering discussions, operated by Hacker News, public threads; Practitioner discussions, operated by Reddit, public threads. Every item carries its source URL and, where the source states one, its date.
Does Microsoft Defender for Office 365 pay to appear in this index?
No. There is no paid placement, no sponsored profile and no way for a vendor to change what the record says. Vendors are listed because their category comes up in enterprise technology decisions. Corrections to a specific entry can be sent to [email protected] and are checked against the source.
How much of the Microsoft Defender for Office 365 record is the vendor's own material?
0 percent. The remaining 100 percent comes from sources Microsoft Defender for Office 365 does not control. Vendor-published material stays in the record and is labelled as vendor-controlled rather than counted as independent confirmation.
Why does this page not say whether Microsoft Defender for Office 365 is better than the alternatives?
Because better only exists relative to a decision. Which criteria matter, how heavily each one weighs and what counts as a dealbreaker are properties of the buyer, not of the vendor. DecisionOS takes this same evidence pool and scores it against the criteria of an actual decision, which is where a comparison becomes meaningful.
How this record is built
Sources are queried on a schedule, not on request. Findings are stored with the source URL, the event date and a content hash, so the same item is never counted twice and every statement stays traceable to where it came from.
Nothing on this page is written by a language model. Counts are counts, dates are the dates the sources carry, and titles are the sources' own wording. Where a section is empty, that is a finding in itself and is stated as one.
Corrections are welcome. If an entry is wrong or an attribution is off, write to [email protected] and it gets checked against the source.
Citing this page
nexalign GmbH, Microsoft Defender for Office 365: what the public record shows, nexalign vendor evidence index, Jul 18, 2026. Available at nexalign.io/vendors/microsoft-defender-for-office-365.
Other vendors in email security
The whole field is on one page: every email security vendor with a published record, with the size of each.
Proofpoint
37 evidence items from 5 sources
Cisco Email Security
36 evidence items from 4 sources
Vade
15 evidence items from 4 sources
Barracuda Email Security
11 evidence items from 4 sources
Mimecast
9 evidence items from 4 sources
Hornetsecurity
6 evidence items from 3 sources
Turn this record into a decision you can defend
DecisionOS takes the same evidence pool this page is built from, weighs it against the criteria of your actual decision, and produces a memo that holds up in front of a board and an auditor.