CVE-2026-20354

MEDIUMPre-NVD 5.95.9
EchelonGraph scoreMEDIUM confidence

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

Score 5.9 from GitHub Security Advisory published 2026-09-02. A secondary CVSS source baseline 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-70210 (ENISA EUVD) · GHSA-x26v-65cq-x3px (GitHub Security Advisories)Source: ENISA EUVD

5.9EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.9Exploit: None knownExposed services: Not assessed

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

Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption functionality of Cisco Secure Email could allow an unauthenticated, remote attacker to recover plain text from encrypted email messages. These vulnerabilities are due to insufficient validation of message integrity. An attacker could exploit these vulnerabilities by using a machine-in-the-middle technique to intercept and modify traffic between email gateways. A successful exploit could allow the attacker to obtain plaintext content from the encrypted communication.

CVSS v3
5.9
EG Score
5.9MEDIUMmedium confidence
EG Risk
27
EG Risk 27/100

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)
Severity59% × 45%
Impact severity (EG Severity): CVSS 5.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.2%
EPSS %ILE
10th
KEV
Not listed

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

The EG score (5.9): severity, escalated by confirmed exploitation. This CVE's 5.9 is its impact severity (EG Severity), not escalated.

EG Severity
5.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (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

Published

September 2, 2026

Last Modified

September 2, 2026

Advisory Details (1)

Auto-updated Sep 2, 2026
No fix on record yet.
Web page

Cisco Secure Email Secure/Multipurpose Internet Mail Extensions Ciphertext Decryption Vulnerabilities

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-smime-disc-dzw4rEdY

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 56× 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 119 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 19 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  2. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  3. 2026-10-25 14:44 UTCEG score recompute
  4. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  5. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  6. 2026-10-23 05:50 UTCEG score recompute
  7. 2026-10-23 05:50 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  8. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  9. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  12. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  13. 2026-10-18 03:57 UTCEG score recompute
  14. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  15. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  16. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  17. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  18. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  19. 2026-10-12 16:24 UTCEG score recompute
  20. 2026-10-11 20:05 UTCEG score recompute
  21. 2026-10-11 17:18 UTCEG score recompute
  22. 2026-10-11 14:50 UTCEG score recompute
  23. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  25. 2026-10-10 00:46 UTCEG score recompute
Show 75 more
  1. 2026-10-10 00:46 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  2. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  3. 2026-10-09 01:39 UTCEG score recompute
  4. 2026-10-09 01:39 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  5. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  6. 2026-10-07 23:41 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  7. 2026-10-06 17:45 UTCEG score recompute
  8. 2026-10-06 17:45 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  9. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-05 18:38 UTCEG score recompute
  11. 2026-10-05 18:38 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  12. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  13. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  14. 2026-10-04 19:31 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  15. 2026-10-03 19:15 UTCEG score recompute
  16. 2026-10-03 19:15 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  17. 2026-10-02 18:49 UTCEG score recompute
  18. 2026-10-02 18:49 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  19. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  20. 2026-10-01 19:39 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  21. 2026-09-30 19:19 UTCEG score recompute
  22. 2026-09-30 19:19 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  23. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-09-29 15:21 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  25. 2026-09-29 14:00 UTCEG score recompute
  26. 2026-09-29 14:00 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  27. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  28. 2026-09-28 13:45 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  29. 2026-09-27 14:35 UTCEG score recompute
  30. 2026-09-27 14:35 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  31. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  32. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  33. 2026-09-26 15:29 UTCEG score recompute
  34. 2026-09-26 15:29 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  35. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  36. 2026-09-25 14:36 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  37. 2026-09-24 15:21 UTCEG score recompute
  38. 2026-09-24 15:21 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  39. 2026-09-24 14:03 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  40. 2026-09-23 15:43 UTCEG score recompute
  41. 2026-09-23 15:43 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  42. 2026-09-22 16:36 UTCEG score recompute
  43. 2026-09-22 16:36 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  44. 2026-09-21 17:13 UTCEG score recompute
  45. 2026-09-21 17:13 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  46. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  47. 2026-09-20 18:06 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  48. 2026-09-19 18:53 UTCEG score recompute
  49. 2026-09-19 18:53 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  50. 2026-09-18 19:44 UTCEG score recompute
  51. 2026-09-18 19:44 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  52. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  53. 2026-09-17 20:37 UTCEG score recompute
  54. 2026-09-17 20:37 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  55. 2026-09-16 18:36 UTCEG score recompute
  56. 2026-09-16 18:36 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  57. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  58. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  59. 2026-09-15 18:20 UTCEG score recompute
  60. 2026-09-15 18:20 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  61. 2026-09-14 19:06 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  62. 2026-09-13 19:59 UTCEG score recompute
  63. 2026-09-13 19:59 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  64. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  65. 2026-09-12 20:52 UTCEG score recompute
  66. 2026-09-12 20:52 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  67. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  68. 2026-09-11 21:45 UTCEG score recompute
  69. 2026-09-11 21:45 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  70. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  71. 2026-09-10 22:38 UTCEG score recompute
  72. 2026-09-10 22:38 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  73. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.1% · 4th percentile
  74. 2026-09-09 23:31 UTCGHSA enrichmentGHSA-x26v-65cq-x3px · GitHub CVSS 5.9
  75. 2026-09-08 23:11 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-20354?
CVE-2026-20354 is a medium-severity vulnerability; its CVE record was published on September 2, 2026. Multiple vulnerabilities in the Secure/Multipurpose Internet Mail Extensions (S/MIME) decryption functionality of Cisco Secure Email could allow an unauthenticated, remote attacker to recover plain text from encrypted email messages. These vulnerabilities are due to insufficient validation of…
When was the CVE record for CVE-2026-20354 published?
The CVE record for CVE-2026-20354 was published on September 2, 2026. 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 September 2, 2026; the record at its source may have been updated since.
Is CVE-2026-20354 actively exploited?
CVE-2026-20354 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (10th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-20354?
CVE-2026-20354 has a CVSS base score of 5.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-20354?
No fix for CVE-2026-20354 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. The vendor advisories EchelonGraph has for CVE-2026-20354 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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