CVE-2026-4257

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-03-31. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Weaponized
9.8EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • Public exploit code is available (Metasploit, epss top5pct, public exploit)
CISA-KEV: Not listedEPSS PROB: 41%CVSS: 9.8Exploit: Metasploit · epss top5pct · public exploitExposed: 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(medium)
EG Risk
85(Track)
EG Risk 85/100SSVC: 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%
Exploitation65% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
41%
EPSS %ILE
99%
KEV
Not listed

Published

March 30, 2026

Last Modified

June 17, 2026

References (3)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 63× 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 165 total refreshes for this CVE.

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

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 June 17, 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 41% probability of exploitation in the next 30 days, which ranks it in the top 1.4% of all scored CVEs.
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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