Microsoft Exchange Server Information Disclosure Vulnerability
Microsoft Exchange Server contains an information disclosure vulnerability that allows for remote code execution.
- Vendor
- Microsoft
- Product
- Exchange Server
- CVSS
- 7.2
- EPSS (exploit probability)
- 54.1%
- Status
- kev
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-31196 being exploited?
Yes. CISA added CVE-2021-31196 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 54.1% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2021-31196 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Microsoft Exchange Server CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-96940 Microsoft Exchange Server privilege escalation via weak authorizationwrite-up | [ HIGH ] | 8.8 | 2.7% | — |
| CVE-2023-21529 Microsoft Exchange Server Deserialization of Untrusted Data Vulnerabilityransomware use | [ HIGH ] | 8.8 | 59.3% | |
| CVE-2024-21410 Microsoft Exchange Server Privilege Escalation Vulnerability | [ CRITICAL ] | 9.8 | 12.7% | |
| CVE-2022-41080 Microsoft Exchange Server Privilege Escalation Vulnerabilityransomware use | [ HIGH ] | 8.8 | 77.3% | |
| CVE-2022-41082 Microsoft Exchange Server Remote Code Execution Vulnerabilityransomware use | [ HIGH ] | 8.0 | 100.0% | |
| CVE-2022-41040 Microsoft Exchange Server Server-Side Request Forgery Vulnerabilityransomware use | [ HIGH ] | 8.8 | 100.0% | |
| CVE-2018-8581 Microsoft Exchange Server Privilege Escalation Vulnerabilityransomware use | [ HIGH ] | 7.4 | 27.6% | |
| CVE-2021-33766 Microsoft Exchange Server Information Disclosure | [ HIGH ] | 7.3 | 98.2% |