What is CVE-2025-8558?

CVE-2025-8558 is a medium-severity vulnerability in Proofpoint Insider Threat Management (Itm) Server, classified under Missing Authentication for Critical Function. CVSS score: 5.4/10. Published 2025-11-03.

How severe is CVE-2025-8558?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Auth bypass in Proofpoint Insider Threat Management (Itm) Server

CVE-2025-8558

Insider Threat Management (ITM) Server versions prior to 7.17.2 contain an authentication bypass vulnerability that allows unauthenticated users on an adjacent network to perform agent unregistration when the number of registered agents exceeds the licensed limit. Successful exploitation prevents the server from receiving new events from affected agents, resulting in a partial loss of integrity and availability with no impact to confidentiality.

Vulnerability class: Broken Authentication

EPSS: 0.006 (45.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L.

Affected products

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

security@proofpoint.com (Broken Link)

Frequently asked questions

What is CVE-2025-8558?: CVE-2025-8558 is a medium-severity vulnerability in Proofpoint Insider Threat Management (Itm) Server, classified under Missing Authentication for Critical Function. CVSS score: 5.4/10. Published 2025-11-03.
How severe is CVE-2025-8558?: Medium severity. CVSS v3 base score is 5.4 out of 10.