Improper Signature VerificationWeakness · CWE-347

CVE-2025-54982

CRITICAL · 9.6 CVSS v3.1 Published 2025-08-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

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

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The vulnerability allows attackers to bypass SAML signature verification on Zscaler's server-side authentication, enabling forged SAML assertions to be accepted as valid. This permits unauthorized authentication and access to protected resources by manipulating the cryptographic signature validation process.

MitigationApply the vendor-supplied patch for CVE-2025-54982 to Zscaler products immediately. If patching is delayed, review SAML IdP configurations and consider additional logging/monitoring for anomalous authentication patterns.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Zscaler SAML authentication is in use
    Review your identity provider (IdP) and service provider (SP) configurations to verify Zscaler is configured as a SAML service provider. Check Zscaler admin console under 'Administration > SAML' or 'Authentication' settings for active SAML configurations.
    Affected if Zscaler is configured as a SAML service provider handling user authentication
  2. Identify Zscaler product and version
    Locate your Zscaler version in the admin console under 'Administration > System Upgrade' or 'Settings'. Note whether you use Zscaler Internet Access (ZIA), Zscaler Private Access (ZPA), or Zscaler Cloud Protection (ZCP).
    Affected if Running an unpatched version of Zscaler that has not received the CVE-2025-54982 fix
  3. Verify SAML signature verification is enabled
    In Zscaler admin console, navigate to 'Administration > SAML Settings' or the SAML configuration page for your IdP. Locate the 'Verify Signature' or 'Signature Required' option and confirm it is enabled or set to 'Always'. Check for any bypass settings.
    Affected if SAML signature verification is disabled, optional, or set to bypass for incoming assertions
  4. Inspect SAML assertion validation settings
    Review the SAML IdP configuration in Zscaler for fields related to certificate validation, including 'Validate Assertion Certificate' or 'Enforce Signed Assertions'. Confirm these are set to require valid cryptographic signatures.
    Affected if Certificate validation is not enforced or is set to optional for SAML assertions
  5. Check SAML IdP metadata integrity
    Review the imported IdP metadata in Zscaler under 'Administration > SAML > IdP Metadata'. Verify the X.509 certificate displayed matches your trusted IdP certificate and has not been replaced or tampered with.
    Affected if IdP metadata contains unexpected certificates or the signing certificate differs from the known trusted source

You are affected if you use Zscaler SAML authentication and either run an unpatched version or have SAML signature verification disabled or not properly enforced on incoming assertions.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied patch for CVE-2025-54982 to Zscaler products immediately. If patching is delayed, review SAML IdP configurations and consider additional logging/monitoring for anomalous authentication patterns.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-54982 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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