CVE-2026-24423

CRITICALNVD 9.89.8
EchelonGraph scoreHIGH confidence

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

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-02-05), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory, NVD CVSS v3
Exploited in the wild

Also known asEUVD-2026-4273 (ENISA EUVD) · GHSA-7jpw-fm5p-f98m (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
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: 88%CVSS: 9.8Exploit: Public PoCExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the ConnectToHub API method. The attacker could point the SmarterMail to the malicious HTTP server, which serves the malicious OS command. This command will be executed by the vulnerable application.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
99
EG Risk 99/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 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: A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; 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
88%
EPSS %ILE
99th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
88% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). 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.

A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; 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://www.smartertools.com/smartermail/release-notes/current · https://www.cve.org/CVERecord?id=CVE-2026-24423 · https://nvd.nist.gov/vuln/detail/CVE-2026-24423

Published

January 23, 2026

Last Modified

August 4, 2026

Advisory Details (4)

Auto-updated Nov 10, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). Fix referenced — no release confirmed yet. Sources: cisa.
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-2026-24423
Web page

SmarterTools SmarterMail < Build 9511 Unauthenticated RCE via ConnectToHub API | Advisories | VulnCheck

https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-rce-via-connecttohub-api
Web page

SmarterMail Additions, Changes and Fixes

https://www.smartertools.com/smartermail/release-notes/current

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 40× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 1,009 rows 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 909 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 06:13 UTCEchelonGraph re-scored
  2. 2026-11-13 06:13 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-11-12 05:42 UTCEchelonGraph re-scored
  4. 2026-11-12 05:42 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-11-11 16:39 UTCEPSS rescoreEPSS 88% · 99th percentile
  6. 2026-11-11 05:13 UTCEchelonGraph re-scored
  7. 2026-11-11 05:13 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-11-10 16:43 UTCEPSS rescoreEPSS 88% · 99th percentile
  9. 2026-11-10 04:44 UTCEchelonGraph re-scored
  10. 2026-11-10 04:44 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-11-09 04:15 UTCEchelonGraph re-scored
  12. 2026-11-09 04:15 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-08 03:39 UTCEchelonGraph re-scored
  14. 2026-11-08 03:39 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-11-07 03:10 UTCEchelonGraph re-scored
  16. 2026-11-07 03:10 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-06 16:37 UTCEPSS rescoreEPSS 88% · 99th percentile
  18. 2026-11-06 02:41 UTCEchelonGraph re-scored
  19. 2026-11-06 02:41 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-11-05 02:12 UTCEchelonGraph re-scored
  21. 2026-11-05 02:12 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-11-04 16:35 UTCEPSS rescoreEPSS 88% · 99th percentile
  23. 2026-11-04 01:43 UTCEchelonGraph re-scored
  24. 2026-11-04 01:43 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-03 01:14 UTCEchelonGraph re-scored
Show 75 more
  1. 2026-11-03 01:14 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  2. 2026-11-02 00:39 UTCEchelonGraph re-scored
  3. 2026-11-02 00:39 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-01 00:10 UTCEchelonGraph re-scored
  5. 2026-11-01 00:10 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-31 16:32 UTCEPSS rescoreEPSS 88% · 99th percentile
  7. 2026-10-30 23:41 UTCEchelonGraph re-scored
  8. 2026-10-30 23:41 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-29 23:12 UTCEchelonGraph re-scored
  10. 2026-10-29 23:12 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-28 22:43 UTCEchelonGraph re-scored
  12. 2026-10-28 22:43 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-27 22:14 UTCEchelonGraph re-scored
  14. 2026-10-27 22:14 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-27 16:31 UTCEPSS rescoreEPSS 88% · 99th percentile
  16. 2026-10-26 21:42 UTCEchelonGraph re-scored
  17. 2026-10-26 21:42 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-25 21:11 UTCEchelonGraph re-scored
  19. 2026-10-25 21:11 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-25 16:32 UTCEPSS rescoreEPSS 88% · 99th percentile
  21. 2026-10-25 14:40 UTCEchelonGraph re-scored
  22. 2026-10-24 20:42 UTCEchelonGraph re-scored
  23. 2026-10-24 20:42 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-23 20:14 UTCEchelonGraph re-scored
  25. 2026-10-23 20:14 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  26. 2026-10-22 19:44 UTCEchelonGraph re-scored
  27. 2026-10-22 19:44 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  28. 2026-10-21 19:16 UTCEchelonGraph re-scored
  29. 2026-10-21 19:15 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  30. 2026-10-21 16:32 UTCEPSS rescoreEPSS 88% · 99th percentile
  31. 2026-10-20 18:46 UTCEchelonGraph re-scored
  32. 2026-10-20 18:46 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-19 18:17 UTCEchelonGraph re-scored
  34. 2026-10-19 18:17 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  35. 2026-10-19 16:31 UTCEPSS rescoreEPSS 88% · 99th percentile
  36. 2026-10-18 17:47 UTCEchelonGraph re-scored
  37. 2026-10-18 17:47 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  38. 2026-10-18 16:31 UTCEPSS rescoreEPSS 88% · 99th percentile
  39. 2026-10-18 03:53 UTCEchelonGraph re-scored
  40. 2026-10-17 17:19 UTCEchelonGraph re-scored
  41. 2026-10-17 17:18 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  42. 2026-10-17 16:33 UTCEPSS rescoreEPSS 88% · 99th percentile
  43. 2026-10-16 16:50 UTCEchelonGraph re-scored
  44. 2026-10-16 16:50 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-15 16:20 UTCEchelonGraph re-scored
  46. 2026-10-15 16:19 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  47. 2026-10-14 16:32 UTCEPSS rescoreEPSS 88% · 99th percentile
  48. 2026-10-14 15:50 UTCEchelonGraph re-scored
  49. 2026-10-14 15:50 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  50. 2026-10-13 15:19 UTCEchelonGraph re-scored
  51. 2026-10-13 15:19 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  52. 2026-10-12 14:49 UTCEchelonGraph re-scored
  53. 2026-10-12 14:49 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  54. 2026-10-12 07:25 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  55. 2026-10-12 03:10 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  56. 2026-10-11 22:56 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-10-11 20:02 UTCEchelonGraph re-scored
  58. 2026-10-11 18:41 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  59. 2026-10-11 17:15 UTCEchelonGraph re-scored
  60. 2026-10-11 14:28 UTCEchelonGraph re-scored
  61. 2026-10-11 14:28 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  62. 2026-10-11 13:48 UTCEPSS rescoreEPSS 88% · 99th percentile
  63. 2026-10-11 10:16 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  64. 2026-10-11 06:03 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-11 01:51 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-10-10 21:37 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  67. 2026-10-10 17:25 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-10-10 13:12 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-10-10 09:00 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  70. 2026-10-10 04:48 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  71. 2026-10-10 00:35 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-10-09 20:22 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-10-09 16:10 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  74. 2026-10-09 11:58 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-10-09 07:45 UTCGHSA enrichmentGHSA-7jpw-fm5p-f98m · GitHub severity CRITICAL · GitHub CVSS 9.8

Publicly available exploits

(2 references)

Public exploit code is referenced for this CVE (1 GitHub PoC), as is 1 Nuclei detection template. A detection template checks whether a system is affected; it is not necessarily exploit code. No release with the fix is confirmed, so defenders should restrict or isolate affected systems accordingly until one is applied.

  • Nucleihttp/cves/2026/CVE-2026-24423.yaml
    Published Apr 17, 2026

    SmarterMail - Remote Code Execution

    Open source ↗
  • GitHub PoCaavamin/CVE-2026-24423
    Published Jan 29, 2026

    CVE-2026-24423 exp

    Open source ↗

Frequently asked(6)

What is CVE-2026-24423?
CVE-2026-24423 is a critical-severity vulnerability; its CVE record was published on January 23, 2026. SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the ConnectToHub API method. The attacker could point the SmarterMail to the malicious HTTP server, which serves the malicious OS command. This command will be executed by the…
When was the CVE record for CVE-2026-24423 published?
The CVE record for CVE-2026-24423 was published on January 23, 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 August 4, 2026; the record at its source may have been updated since.
Is CVE-2026-24423 actively exploited?
Yes. CISA added CVE-2026-24423 to the Known Exploited Vulnerabilities catalog on February 5, 2026, affecting SmarterTools SmarterMail. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation.
What is the CVSS score of CVE-2026-24423?
CVE-2026-24423 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2026-24423?
CVE-2026-24423 affects SmarterTools SmarterMail.
How do I remediate CVE-2026-24423?
A fix for CVE-2026-24423 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-24423

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