Vulnerability in Zscaler Authentication Server

CVE-2025-54982

An improper verification of cryptographic signature in Zscaler's SAML authentication mechanism on the server-side allowed an authentication abuse.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (31.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-54982: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-54982?
CVE-2025-54982 is a critical-severity vulnerability in Zscaler Authentication Server, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.6/10. Published 2025-08-05.
How severe is CVE-2025-54982?
Critical severity. CVSS v3 base score is 9.6 out of 10.