Microsoft Exchange Information Disclosure Vulnerability
Priority LOW 36Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
<p>An information disclosure vulnerability exists in how Microsoft Exchange validates tokens when handling certain messages. An attacker who successfully exploited the vulnerability could use this to gain further information from a user.</p> <p>To exploit the vulnerability, an attacker could include specially crafted OWA messages that could be loaded, without warning or filtering, from the attacker-controlled URL. This callback vector provides an information disclosure tactic used in web beacons and other types of tracking systems.</p> <p>The security update corrects the way that Exchange handles these token validations.</p>
Why it matters now
EPSS 0.0273 86th percentileScored 2026-11-07
Fix Fixed Microsoft Exchange Server 2019 Cumulative Update 6 (Microsoft): publicationMicrosoft Exchange Server 2016 Cumulative Update 17 (Microsoft): publication+3 more products
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 6 | 15.02.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 17 | 15.01.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 7 | 15.02.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 18 | 15.01.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 23 | 15.00.0 to before publication | publication | Patch available | CNA |
- Microsoft Exchange Server 2019 Cumulative Update 6 VendorMicrosoft Affected 15.02.0 to before publication Fixed in publication Patch available CNA
- Microsoft Exchange Server 2016 Cumulative Update 17 VendorMicrosoft Affected 15.01.0 to before publication Fixed in publication Patch available CNA
- Microsoft Exchange Server 2019 Cumulative Update 7 VendorMicrosoft Affected 15.02.0 to before publication Fixed in publication Patch available CNA
- Microsoft Exchange Server 2016 Cumulative Update 18 VendorMicrosoft Affected 15.01.0 to before publication Fixed in publication Patch available CNA
- Microsoft Exchange Server 2013 Cumulative Update 23 VendorMicrosoft Affected 15.00.0 to before publication Fixed in publication Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:* | 2013 cumulative_update_23 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17:*:*:*:*:*:* | 2016 cumulative_update_17 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18:*:*:*:*:*:* | 2016 cumulative_update_18 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6:*:*:*:*:*:* | 2019 cumulative_update_6 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:* | 2019 cumulative_update_7 | Vulnerable | Microsoft |
- cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:* Versions 2013 cumulative_update_23 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17:*:*:*:*:*:* Versions 2016 cumulative_update_17 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18:*:*:*:*:*:* Versions 2016 cumulative_update_18 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6:*:*:*:*:*:* Versions 2019 cumulative_update_6 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:* Versions 2019 cumulative_update_7 Vulnerable ·Microsoft
Remediation
- Fix · CNA Microsoft Exchange Server 2019 Cumulative Update 6 (Microsoft) Fixed in publication
- Fix · CNA Microsoft Exchange Server 2016 Cumulative Update 17 (Microsoft) Fixed in publication
- Fix · CNA Microsoft Exchange Server 2019 Cumulative Update 7 (Microsoft) Fixed in publication
- Fix · CNA Microsoft Exchange Server 2016 Cumulative Update 18 (Microsoft) Fixed in publication
- Fix · CNA Microsoft Exchange Server 2013 Cumulative Update 23 (Microsoft) Fixed in publication
Timeline
- 2026-10-02 Threatist record created from CVE-2020-16969
- 2026-10-03 Alias added: GHSA-hx67-2mh4-8cj2
More Microsoft Exchange Server vulnerabilities
- TI-2024-14170 Microsoft Exchange Server Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2022-19610 Microsoft Exchange Server Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2021-13547 Microsoft Exchange Server Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2021-13502 Microsoft Exchange Server Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2021-08465 Microsoft Exchange Server Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2023-07929 Microsoft Exchange Server Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2020-16969 · CVE Program
- CVE-2020-16969 · NVD
- FIRST EPSS
- GHSA-hx67-2mh4-8cj2 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences