CVE-2026-4257

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because EPSS predicts 87% probability of exploitation within the next 30 days (top 0.5% of all CVEs). NVD baseline CVSS 9.8 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, ghsa, nvd
Weaponized
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 41%CVSS: 9.8Exploit: NoneExposed: 0

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

The Contact Form by Supsystic plugin for WordPress is vulnerable to Server-Side Template Injection (SSTI) leading to Remote Code Execution (RCE) in all versions up to, and including, 1.7.36. This is due to the plugin using the Twig Twig_Loader_String template engine without sandboxing, combined with the cfsPreFill prefill functionality that allows unauthenticated users to inject arbitrary Twig expressions into form field values via GET parameters. This makes it possible for unauthenticated attackers to execute arbitrary PHP functions and OS commands on the server by leveraging Twig's registerUndefinedFilterCallback() method to register arbitrary PHP callbacks.

CVSS v3
9.8
EG Score
9.8(high)
EPSS
98.5%
KEV
Not listed

Published

March 30, 2026

Last Modified

April 24, 2026

References (3)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 27× 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 108 total refreshes for this CVE.

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

Publicly available exploits

(3 references)

Working exploit code is in the public domain (1 Metasploit module) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-52564
    First seen May 14, 2026

    WordPress Plugin Supsystic Contact Form 1.7.36 - SSTI

    Open source ↗
  • Metasploitexploit/multi/http/wp_plugin_supsystic_contact_form_rce✓ verified
    First seen Mar 30, 2026

    Supsystic Contact Form Wordpress Plugin SSTI RCE

    Open source ↗
  • Nucleihttp/cves/2026/CVE-2026-4257.yaml
    First seen Jan 1, 2026

    WordPress Contact Form by Supsystic - Server-Side Template Injection

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-4257?
CVE-2026-4257 is a critical vulnerability published on March 30, 2026. The Contact Form by Supsystic plugin for WordPress is vulnerable to Server-Side Template Injection (SSTI) leading to Remote Code Execution (RCE) in all versions up to, and including, 1.7.36. This is due to the plugin using the Twig TwigLoaderString template engine without sandboxing, combined with…
When was CVE-2026-4257 disclosed?
CVE-2026-4257 was first published in the National Vulnerability Database on March 30, 2026, with the most recent update on April 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4257 actively exploited?
CVE-2026-4257 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-4257?
CVE-2026-4257 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-4257?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4257, 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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