high Known exploitedREV. 01

CVE-2021-31196Microsoft Exchange Server — disclosure that ends in code execution

Microsoft's advisory calls this an Exchange Server remote code execution flaw; the federal catalog entry describes it as information disclosure that leads to code execution. Neither source names the affected component or the preconditions.

YOUR NEXT MOVE

Install the Microsoft security update for CVE-2021-31196 on every Exchange Server; the advisory is the only source that names the fixed builds.

Read the risk

THE VITAL STATS
CVSS score
7.2/ 10
CVSS v3.1
EPSS probability
54%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2021-07-14
Added to KEV
2024-08-21
Exploit published
Not recorded
Confidence
medium
Kill chain
execution
MITRE ATT&CK
—
Severity
high

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

Behind the card

4 REFERENCES
Field-level provenanceTRACE THE SOURCES +

Which source supports each field, when it was retrieved, and who extracted it.

FieldsSourceRetrievedExtractorConfidence
cvss, exploitation.attack_complexity, exploitation.exploit_available, references, published_atnvd.nist.gov2026-09-24scrty-crds-pipeline/0.1high
exploitation.known_exploited, exploitation.kev_addedcisa.gov2026-09-24scrty-crds-pipeline/0.1high
epssapi.first.org2026-09-24scrty-crds-pipeline/0.1high
title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisitesnvd.nist.gov2026-09-24claude-codehigh

Printing history

THE RECORD
  1. r1Initial base card

First printing. This card has not been reprinted since publication.

crds:cve-2021-31196 · CRDS 0.1 · Issued 2026-09-24