CVE-2022-21855

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

0.92% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 60.1% of scored records. A rank, not a probability.

NVD base score

9.0 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2022-01-11 20:22Z4 YR AGO

Last updated

2025-01-02 18:22Z1 YR AGO

Reserved

2021-12-14

Assigning CNA

microsoft

Record state

PUBLISHED

Severity

Critical (CVSS 9.0)

CNA CVSS vector

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C

Weaknesses

No CWE assigned

Data version

5.1

Document digest

17fe8c2328c30f26f932b5c1952816416b24c209ec04ead3f69f657beba2d6e6

• msrc.microsoft.comMicrosoft Exchange Server Remote Code Execution Vulnerabilityhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-21855vendor-advisory
• portal.msrc.microsoft.comhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-21855x_refsource_MISC