high Known exploitedREV. 01

CVE-2025-21391Windows Storage — link following deletes data as the service

The Windows storage service follows a link without checking where it points, so a local user can have it delete files they should never reach — enough to take the service down with them.

YOUR NEXT MOVE

Install the Microsoft update for this CVE now; the impact is deletion rather than theft, so check for services that failed to start after an incident.

Read the risk

THE VITAL STATS
CVSS score
7.1/ 10
CVSS v3.1
EPSS probability
2%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2025-02-11
Added to KEV
2025-02-11
Exploit published
Not recorded
Confidence
high
Kill chain
privilege escalation
MITRE ATT&CK
T1068
Severity
high

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

Attacker needsAn existing local account on the machine.

Behind the card

3 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-2025-21391 · CRDS 0.1 · Issued 2026-09-24