high Known exploitedREV. 01

CVE-2020-0688Microsoft Exchange — Static Key to Code Execution

Every Microsoft Exchange server shipped with the same built-in secret key, so any user with a mailbox can sign a crafted request and run code on the server with system privileges.

YOUR NEXT MOVE

Apply Microsoft's cumulative update for Exchange, then rotate the machine keys on every server in the organisation.

Read the risk

THE VITAL STATS
CVSS score
8.8/ 10
CVSS v3.1
EPSS probability
100%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2020-02-11
Added to KEV
2021-11-03
Exploit published
Yes
Confidence
high
Kill chain
privilege escalation
MITRE ATT&CK
T1190
Severity
high

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

Attacker needsAny valid mailbox account

Behind the card

5 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.gov2026-08-07scrty-crds-pipeline/0.1high
exploitation.known_exploited, exploitation.kev_addedcisa.gov2026-08-07scrty-crds-pipeline/0.1high
epssapi.first.org2026-08-07scrty-crds-pipeline/0.1high
title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisitesnvd.nist.gov2026-08-07claude-codehigh

Printing history

THE RECORD
  1. r1Initial base card

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

crds:cve-2020-0688 · CRDS 0.1 · Issued 2026-08-07