What is CVE-2026-4257?

CVE-2026-4257 is a critical-severity vulnerability in Supsysticcom Contact Form By Supsystic, classified under Code Injection. CVSS score: 9.8/10. Published 2026-03-30.

How severe is CVE-2026-4257?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2026-4257 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Supsysticcom Contact Form By Supsystic

CVE-2026-4257

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_L…

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.867 (99.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Supsysticcom Contact Form By Supsystic — versions 0

Weakness classification (CWE)

CWE-94 — Code Injection

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-4257?: CVE-2026-4257 is a critical-severity vulnerability in Supsysticcom Contact Form By Supsystic, classified under Code Injection. CVSS score: 9.8/10. Published 2026-03-30.
How severe is CVE-2026-4257?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-4257 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.