CVE-2025-54982: Zscaler Authentication Server

Critical severity, CVSS 9.6. EPSS: 0.4% chance of exploitation in the next 30 days.

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

Affected products

• Zscaler Authentication Server: before 6.2r (fixed in 6.2r)

Published 2025-08-05. Last modified 2026-06-17.