Akamai Ghost on Akamai CDN edge servers before 2025-11-17 has a chunked request body processing error that can result in HTTP request smuggling. When Akamai Ghost receives an invalid chunked body that includes a chunk size different from the actual size of the following chunk data, under certain circumstances, Akamai Ghost erroneously forwards the invalid request and subsequent superfluous bytes to the origin server. An attacker could hide a smuggled request in these superfluous bytes. Whether this is exploitable depends on the origin server's behavior and how it processes the invalid request it receives from Akamai Ghost.
Conclusion & alert: CVE-2025-66373 is rated Low Risk (24.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.23%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
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 | 0.03% | 0.23% | +0.20% |
| 2 | 2026-05-01 | 0.05% | 0.03% | -0.02% |
| 3 | 2026-02-10 | — | 0.05% | — |
Full EPSS history (4 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.8 | 3.1 | MEDIUM |
|
2.2 | 2.5 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| akamai | akamaighost | < 2025-11-17 | cpe:2.3:a:akamai:akamaighost:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://en.wikipedia.org/wiki/HTTP_request_smuggling | Technical Description |
| https://www.akamai.com/blog/security/cve-2025-66373-http-request-smuggling-chunked-body-size | Mitigation Vendor Advisory |