CVE-2026-4883

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-19. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

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

The Piotnet Forms plugin for WordPress is vulnerable to arbitrary file upload due to missing file type validation in the 'piotnetforms_ajax_form_builder' function in all versions up to, and including, 2.1.40. The plugin uses an incomplete extension blacklist that only blocks php, phpt, php5, php7, and exe extensions, while allowing dangerous extensions such as .phar or .phtml to be uploaded. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible. Note: The exploit can only be exploited if a file field is added to the form.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
54%
KEV
Not listed

Published

May 19, 2026

Last Modified

May 19, 2026

Advisory Details (1)

Auto-updated Aug 26, 2026
No patch confirmed yet.
generic

Piotnet Forms - Highly Customizable WordPress Form Builder

https://piotnetforms.com

Vendor Advisories for CVE-2026-4883(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 8× in last 7d / 107× 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 303 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-4883?
CVE-2026-4883 is a critical vulnerability published on May 19, 2026. The Piotnet Forms plugin for WordPress is vulnerable to arbitrary file upload due to missing file type validation in the 'piotnetformsajaxform_builder' function in all versions up to, and including, 2.1.40. The plugin uses an incomplete extension blacklist that only blocks php, phpt, php5, php7,…
When was CVE-2026-4883 disclosed?
CVE-2026-4883 was first published in the National Vulnerability Database on May 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4883 actively exploited?
CVE-2026-4883 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 46.1% of all scored CVEs.
What is the CVSS score of CVE-2026-4883?
CVE-2026-4883 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-4883?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4883, 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.

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