CVE-2026-70571: Microsoft Exchange Server Remote Code Execution Vulnerability
Stack-based buffer overflow in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
- Published by source
- 2026-10-13
- First seen by Reality Radar
- 2026-10-22
- Last verified
- 2026-10-22
Affected
- Manufacturer
- Microsoft
- Products
- Microsoft Exchange Server 2019 Cumulative Update 15 Microsoft Exchange Server Subscription Edition RTM Microsoft Exchange Server 2016 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 14
- CPE
- cpe:2.3:a:microsoft:exchange_server_2019:*:cumulative_update_15:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server_se:*:RTM:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server_2016:*:cumulative_update_23:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server_2019:*:cumulative_update_14:*:*:*:*:*:*
Whether your exact unit is affected depends on the model, serial number and region in the official notice.
What the official notice says
Risk: Critical — Remote Code Execution
Remedy / actions:
- Install the security update: https://support.microsoft.com/help/5128896
Is this affecting you?
Add what you own or use and Reality Radar will tell you when official changes match it — with evidence and next steps.
Sources
- Microsoft Security Update Guide (MSRC) Tier A · official published 2026-10-13
Evidence ledger
Every piece of evidence we store is appended to a public hash chain, so later edits are detectable. Anyone can re-verify it.
| Entry | Kind | Observed | Evidence hash | Entry hash |
|---|---|---|---|---|
| #144 | new | 2026-10-22 | d376e1734fc8…76e911 | 67371678243f…773627 |
Chain head: #1076 8ad5adc30b9b…88ce20