critical Known exploitedREV. 01

CVE-2025-20393Cisco Secure Email Gateway — quarantine flaw to root execution

The spam quarantine in Cisco's email security appliances does not validate requests properly, letting an unauthenticated attacker run system commands as root on the gateway that filters the organisation's mail.

YOUR NEXT MOVE

Apply Cisco advisory cisco-sa-sma-attack-N9bf4 now; the gateway sees all inbound mail, so review quarantine access logs and rotate its credentials.

Read the risk

THE VITAL STATS
CVSS score
10.0/ 10
CVSS v3.1
EPSS probability
30%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2025-12-17
Added to KEV
2025-12-17
Exploit published
Not recorded
Confidence
high
Kill chain
initial access
MITRE ATT&CK
T1190
Severity
critical

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

Attacker needsNetwork access to the spam quarantine interface; no credentials needed.

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-2025-20393 · CRDS 0.1 · Issued 2026-09-24