CVE-2025-20393

CRITICALNVD 10.010.0
EchelonGraph scoreHIGH confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score elevated to 10.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2025-12-17), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 10.0 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this weekExploited in the wild

Also known asEUVD-2025-203911 (ENISA EUVD) · GHSA-mrgj-cg36-fgq8 (GitHub Security Advisories)Source: ENISA EUVD

10.0EG
EchelonGraph verdictMitigate nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low mission impact
CISA-KEV: ExploitedEPSS PROB: 32%CVSS: 10.0Exploit: Public PoCExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager could allow an unauthenticated, remote attacker to execute arbitrary system commands on an affected device with root privileges. This vulnerability is due to insufficient validation of HTTP requests by the Spam Quarantine feature. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.

CVSS v3
10.0
EG Score
10.0CRITICALhigh confidence
EG Risk
100
EG Risk 100/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity100% × 45%
Impact severity (EG Severity): CVSS 10.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Attend at low mission impact; Act at medium or high.
Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation sooner than your normal schedule at low mission impact and as soon as possible at medium or high.
EPSS PROB
32%
EPSS %ILE
98th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (10.0): severity, escalated by confirmed exploitation. This CVE's 10.0 is its impact severity (EG Severity), not escalated.

EG Severity
10.0 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
32% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Act at medium mission impactAttend at low mission impact; Act at medium or high.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: this CVE is in CISA's KEV catalog, and CISA's required action for it, quoted below, applies whether or not a fix is released.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Attend at low mission impact; Act at medium or high.

No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation sooner than your normal schedule at low mission impact and as soon as possible at medium or high.

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: this CVE is in CISA's KEV catalog, and CISA's required action for it, quoted below, applies whether or not a fix is released.

The score's inputs: In CISA KEV yes (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

CISA required action“Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4 · https://nvd.nist.gov/vuln/detail/CVE-2025-20393

Published

December 17, 2025

Last Modified

October 7, 2026

Advisory Details (2)

Auto-updated Oct 29, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). No fix on record yet.
Web page

Reports About Cyberattacks Against Cisco Secure Email Gateway And Cisco Secure Email and Web Manager

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4
CISA🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20393

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 21× in last 7d / 136× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 1,132 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 1,032 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 00:24 UTCEG score recompute
  2. 2026-11-02 00:24 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  3. 2026-11-01 02:43 UTCEG score recompute
  4. 2026-11-01 02:43 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  5. 2026-10-31 16:30 UTCEPSS rescoreEPSS 32% · 98th percentile
  6. 2026-10-31 05:00 UTCEG score recompute
  7. 2026-10-31 05:00 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  8. 2026-10-30 16:32 UTCEPSS rescoreEPSS 32% · 98th percentile
  9. 2026-10-30 07:18 UTCEG score recompute
  10. 2026-10-30 07:18 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  11. 2026-10-29 16:31 UTCEPSS rescoreEPSS 32% · 98th percentile
  12. 2026-10-29 09:36 UTCEG score recompute
  13. 2026-10-29 09:36 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  14. 2026-10-28 16:30 UTCEPSS rescoreEPSS 32% · 98th percentile
  15. 2026-10-28 11:54 UTCEG score recompute
  16. 2026-10-28 11:54 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  17. 2026-10-27 16:30 UTCEPSS rescoreEPSS 32% · 98th percentile
  18. 2026-10-27 14:12 UTCEG score recompute
  19. 2026-10-27 14:12 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  20. 2026-10-26 16:29 UTCEPSS rescoreEPSS 32% · 98th percentile
  21. 2026-10-26 16:27 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  22. 2026-10-25 22:11 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  23. 2026-10-25 16:44 UTCEG score recompute
  24. 2026-10-25 16:31 UTCEPSS rescoreEPSS 32% · 98th percentile
  25. 2026-10-25 00:28 UTCEG score recompute
Show 75 more
  1. 2026-10-25 00:28 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  2. 2026-10-24 02:46 UTCEG score recompute
  3. 2026-10-24 02:46 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  4. 2026-10-23 16:30 UTCEPSS rescoreEPSS 32% · 98th percentile
  5. 2026-10-23 05:03 UTCEG score recompute
  6. 2026-10-23 05:03 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  7. 2026-10-22 16:32 UTCEPSS rescoreEPSS 32% · 98th percentile
  8. 2026-10-22 07:19 UTCEG score recompute
  9. 2026-10-22 07:19 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  10. 2026-10-21 16:30 UTCEPSS rescoreEPSS 32% · 98th percentile
  11. 2026-10-21 09:37 UTCEG score recompute
  12. 2026-10-21 09:37 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  13. 2026-10-20 16:31 UTCEPSS rescoreEPSS 32% · 98th percentile
  14. 2026-10-20 11:55 UTCEG score recompute
  15. 2026-10-20 11:55 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  16. 2026-10-19 16:30 UTCEPSS rescoreEPSS 32% · 98th percentile
  17. 2026-10-19 14:12 UTCEG score recompute
  18. 2026-10-19 14:11 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  19. 2026-10-18 16:28 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  20. 2026-10-18 14:45 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  21. 2026-10-18 05:47 UTCEG score recompute
  22. 2026-10-17 17:03 UTCEG score recompute
  23. 2026-10-17 17:02 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  24. 2026-10-17 16:32 UTCEPSS rescoreEPSS 32% · 98th percentile
  25. 2026-10-16 19:20 UTCEG score recompute
  26. 2026-10-16 19:20 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  27. 2026-10-16 16:38 UTCEPSS rescoreEPSS 32% · 98th percentile
  28. 2026-10-15 21:38 UTCEG score recompute
  29. 2026-10-15 21:37 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  30. 2026-10-15 16:30 UTCEPSS rescoreEPSS 32% · 98th percentile
  31. 2026-10-14 23:55 UTCEG score recompute
  32. 2026-10-14 23:55 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  33. 2026-10-14 16:31 UTCEPSS rescoreEPSS 32% · 98th percentile
  34. 2026-10-14 02:12 UTCEG score recompute
  35. 2026-10-14 02:11 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  36. 2026-10-13 16:32 UTCEPSS rescoreEPSS 32% · 98th percentile
  37. 2026-10-13 04:28 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  38. 2026-10-12 17:21 UTCEG score recompute
  39. 2026-10-12 16:32 UTCEPSS rescoreEPSS 32% · 98th percentile
  40. 2026-10-12 06:44 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  41. 2026-10-12 02:45 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  42. 2026-10-11 22:47 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  43. 2026-10-11 20:52 UTCEG score recompute
  44. 2026-10-11 18:49 UTCEG score recompute
  45. 2026-10-11 18:49 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  46. 2026-10-11 14:51 UTCEG score recompute
  47. 2026-10-11 14:51 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  48. 2026-10-11 13:47 UTCEPSS rescoreEPSS 32% · 98th percentile
  49. 2026-10-11 10:53 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  50. 2026-10-11 06:55 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  51. 2026-10-11 02:57 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  52. 2026-10-10 22:58 UTCEG score recompute
  53. 2026-10-10 22:58 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  54. 2026-10-10 19:59 UTCEPSS rescoreEPSS 32% · 98th percentile
  55. 2026-10-10 18:59 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  56. 2026-10-10 15:01 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  57. 2026-10-10 11:03 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  58. 2026-10-10 07:04 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  59. 2026-10-10 03:05 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  60. 2026-10-09 23:08 UTCEG score recompute
  61. 2026-10-09 23:07 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  62. 2026-10-09 20:06 UTCEPSS rescoreEPSS 32% · 98th percentile
  63. 2026-10-09 19:09 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  64. 2026-10-09 15:11 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  65. 2026-10-09 11:14 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  66. 2026-10-09 07:15 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  67. 2026-10-09 03:17 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  68. 2026-10-08 23:19 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  69. 2026-10-08 19:22 UTCEG score recompute
  70. 2026-10-08 19:21 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  71. 2026-10-08 17:09 UTCEPSS rescoreEPSS 32% · 98th percentile
  72. 2026-10-08 15:23 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  73. 2026-10-08 11:25 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  74. 2026-10-08 07:26 UTCGHSA enrichmentGHSA-mrgj-cg36-fgq8 · GitHub severity CRITICAL · GitHub CVSS 10.0
  75. 2026-10-08 03:28 UTCEG score recompute

Publicly available exploits

(2 references)

Public exploit code is referenced for this CVE (1 GitHub PoC), as is 1 GitHub checker repository. A GitHub repository named or described as a checker or scanner checks whether a system is affected; it is not necessarily exploit code. No fix is confirmed yet, so defenders should restrict or isolate affected systems accordingly until one is published.

  • GitHub checkerStasonJatham/cisco-sa-sma-attack-N9bf4
    Published Dec 18, 2025

    Script to detect CVE-2025-20393 for Cisco Secure Email Gateway And Cisco Secure Email and Web Manager

    Open source ↗
  • GitHub PoCcyberleelawat/CVE-2025-20393
    Published Dec 18, 2025

    Cisco is aware of a potential vulnerability.  Cisco is currently investigating and will update these details as appropriate as more information becomes available.

    Open source ↗

Frequently asked(6)

What is CVE-2025-20393?
CVE-2025-20393 is a critical-severity vulnerability; its CVE record was published on December 17, 2025. A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager could allow an unauthenticated, remote attacker to execute arbitrary system commands on an affected device with root privileges. This vulnerability is due…
When was the CVE record for CVE-2025-20393 published?
The CVE record for CVE-2025-20393 was published on December 17, 2025. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 7, 2026; the record at its source may have been updated since.
Is CVE-2025-20393 actively exploited?
Yes. CISA added CVE-2025-20393 to the Known Exploited Vulnerabilities catalog on December 17, 2025, affecting Cisco Multiple Products. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation.
What is the CVSS score of CVE-2025-20393?
CVE-2025-20393 has a CVSS v3 base score of 10.0 (NVD).
Which products are affected by CVE-2025-20393?
CVE-2025-20393 affects Cisco Multiple Products.
How do I remediate CVE-2025-20393?
No fix for CVE-2025-20393 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2025-20393

Explore →

Is Your Infrastructure Affected by CVE-2025-20393?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.