CVE-2025-66373

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.25% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 17.3% of scored records. A rank, not a probability.

NVD base score

4.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2025-12-04 00:00Z10 MO AGO

Last updated

2025-12-08 16:22Z10 MO AGO

Reserved

2025-11-28

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 4.8)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Weaknesses

• CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')Base

Data version

5.2

Document digest

48d6f8b4c4eeab81cee86601ccfd1702cff51da86b7f4b686bdb3c201cabddb0

• en.wikipedia.orghttps://en.wikipedia.org/wiki/HTTP_request_smuggling
• www.akamai.comhttps://www.akamai.com/blog/security/cve-2025-66373-http-request-smuggling-chunked-body-size