Regular expression Denial-of-Service (ReDoS) exists in multiple add-ons for Mailform Pro CGI 4.3.1.3 and earlier, which allows a remote unauthenticated attacker to cause a denial-of-service condition. Affected add-ons are as follows: call/call.js, prefcodeadv/search.cgi, estimate/estimate.js, search/search.js, suggest/suggest.js, and coupon/coupon.js.
Conclusion & alert: CVE-2023-40599 is rated Moderate Risk (46.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.67%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.88% | 0.67% | -0.21% |
| 2 | 2026-06-07 | 0.68% | 0.88% | +0.21% |
| 3 | 2026-05-20 | — | 0.68% | — |
Full EPSS history (16 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| synck_graphica | mailform_pro_cgi | <= 4.3.1.3 | cpe:2.3:a:synck_graphica:mailform_pro_cgi:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://jvn.jp/en/jp/JVN86484824/ | Third Party Advisory |
| https://www.synck.com/blogs/news/newsroom/detail_1691668841.html | Vendor Advisory |