9.6

CVE-2025-54982: zscaler authentication server

CVSS: 9.6v3.1CriticalDeferred
Published 05-08-2025Last modified 26-02-2026
Open JSON

Vulnerability summary

CVE-2025-54982 is a critical (CVSS 9.6) vulnerability in zscaler authentication server. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 32.3% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.6/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.40%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 05-08-2025
    PublishedVulnerability first disclosed.
  2. 26-02-2026
    Last modifiedVulnerability information updated.

Description

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

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

32%

Versus all other CVEs

30-day change

0.00 pp

From 0.40% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.40%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Zscaler1 product

1 vendor · 1 product

References

1 links