{"basis":"claimed","id":"CVE-2026-4257","name":"Contact Form by Supsystic <= 1.7.36 - Unauthenticated Server-Side Template Injection via Prefill Functionality","vendorProject":"supsysticcom","product":"Contact Form by Supsystic","publishedAt":"2026-03-30","cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1"},"exploited":null,"epss":{"score":0.41475,"percentile":0.98678,"date":"2026-11-02"},"coverage":{"cloudflare":{"status":"none","firstOn":null,"daysToRule":null},"aws":{"status":"none","firstOn":null,"daysToRule":null},"azure":{"status":"none","firstOn":null,"daysToRule":null},"google":{"status":"none","firstOn":null,"daysToRule":null},"fastly":{"status":"no_history","firstOn":null,"daysToRule":null},"f5":{"status":"rule","firstOn":"2026-09-16","daysToRule":170},"akamai":{"status":"no_source","firstOn":null,"daysToRule":null},"crs":{"status":"none","firstOn":null,"daysToRule":null}},"title":"Contact Form by Supsystic <= 1.7.36 - Unauthenticated Server-Side Template Injection via Prefill Functionality","description":"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.","cwes":["CWE-94"],"vendors":[{"vendor":"cloudflare","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"aws","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"azure","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"google","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"fastly","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"f5","status":"rule","basis":"claimed","firstOn":"2026-09-16","firstIsNew":true,"daysToRule":170,"daysAtMost":null,"freePlan":false,"claims":[{"id":"965549077cd81959287e6f9a45397b6542b4bfea6aea6f1bb2c9d59f246391ea","cve_id":"CVE-2026-4257","vendor":"f5","product":"Attack signatures","rule_id":"200204084","rule_name":"WordPress Contact Form Plugin SSTI","change":"new","default_action":null,"published_on":"2026-09-16","source_url":"https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog","source_title":"F5 Distributed Cloud attack signatures changelog","excerpt":"Added: signature 200204084 \"WordPress Contact Form Plugin SSTI\" (Server Side Code Injection, risk High), systems: WordPress. References: CVE-2026-4257.","first_seen_at":"2026-11-02T21:00:24.509Z"}]},{"vendor":"akamai","status":"no_source","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"crs","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]}],"updatedAt":"2026-11-02T21:16:35.125Z","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total"},"measured":[{"engineId":"owasp-crs","engineName":"OWASP Core Rule Set","engineVersion":"4.25.0","runtime":"Coraza v3.8.1","config":"paranoia level 1, anomaly threshold 5, default CRS settings","ranAt":"2026-11-02T13:02:57.000Z","verdict":"passed","templateId":"CVE-2026-4257","templatePath":"http/cves/2026/CVE-2026-4257.yaml","requests":2,"blockedRequests":0,"rules":[],"note":"","requestDetail":[{"method":"GET","path":"/","status":200,"blocked":false,"rules":[]},{"method":"GET","path":"/xcfsPreFill=1&first_name=%7B%7B43797*41137%7D%7D","status":200,"blocked":false,"rules":[]}]},{"engineId":"owasp-crs","engineName":"OWASP Core Rule Set","engineVersion":"4.25.0","runtime":"Coraza v3.8.1","config":"paranoia level 2, anomaly threshold 5, default CRS settings","ranAt":"2026-11-02T13:03:28.000Z","verdict":"partial","templateId":"CVE-2026-4257","templatePath":"http/cves/2026/CVE-2026-4257.yaml","requests":2,"blockedRequests":1,"rules":["941380"],"note":"","requestDetail":[{"method":"GET","path":"/","status":200,"blocked":false,"rules":[]},{"method":"GET","path":"/xcfsPreFill=1&first_name=%7B%7B43797*41137%7D%7D","status":403,"blocked":true,"rules":["941380"]}]}],"social":{"total":0,"first_seen":null,"daily":[{"day":"2026-10-21","posts":0},{"day":"2026-10-22","posts":0},{"day":"2026-10-23","posts":0},{"day":"2026-10-24","posts":0},{"day":"2026-10-25","posts":0},{"day":"2026-10-26","posts":0},{"day":"2026-10-27","posts":0},{"day":"2026-10-28","posts":0},{"day":"2026-10-29","posts":0},{"day":"2026-10-30","posts":0},{"day":"2026-10-31","posts":0},{"day":"2026-11-01","posts":0},{"day":"2026-11-02","posts":0},{"day":"2026-11-03","posts":0}],"top_posts":[],"exploit_repositories":[]}}