CVE-2026-27064

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-23. a secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

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

Editor Arbitrary File Upload in Mailster <= 4.1.17 versions.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
41%
KEV
Not listed

Published

July 23, 2026

Last Modified

July 23, 2026

Advisory Details (1)

Auto-updated Sep 7, 2026
No patch confirmed yet.
generic

Arbitrary File Upload in WordPress Mailster Plugin - Patchstack

https://patchstack.com/database/wordpress/plugin/mailster/vulnerability/wordpress-mailster-plugin-4-1-17-arbitrary-file-upload-vulnerability?_s_id=cve

Vendor Advisories for CVE-2026-27064(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 30× in last 7d / 151× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 329 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-27064?
CVE-2026-27064 is a critical vulnerability published on July 23, 2026. Editor Arbitrary File Upload in Mailster <= 4.1.17 versions.
When was CVE-2026-27064 disclosed?
CVE-2026-27064 was first published in the National Vulnerability Database on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27064 actively exploited?
CVE-2026-27064 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 58.7% of all scored CVEs.
What is the CVSS score of CVE-2026-27064?
CVE-2026-27064 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-27064?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27064, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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