CVE-2026-66901: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-xxpm-5c34-x4c3
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CVSS 7.5
CWE-201
Published
Advisory Summary

CVE-2026-66901 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-201: Insertion of Sensitive Information Into Sent Data) affecting Software libraries in the Maven ecosystem. The weakness occurs when the code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-66901 at a Glance

CVE Identifier CVE-2026-66901
GHSA Identifier GHSA-xxpm-5c34-x4c3
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-201: Insertion of Sensitive Information Into Sent Data
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-66901

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-66901, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-201: Insertion of Sensitive Information Into Sent Data, where the code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Google::Auth versions before 0.09 for Perl allow server side request forgery and credential exfiltration via unvalidated URLs taken from the credentials JSON. The URLs the library requests are read from the credentials JSON, and their hosts were not checked against the universe domain before the request. For an external_account configuration, retrieve_subject_token fetched credential_source.url with headers from the same JSON, and fetch_access_token posted the subject token to token_url, then sent the STS access token it received to service_account_impersonation_url in an Authorization: Bearer header. The authorized_user, impersonated_service_account and service_account configurations posted the client secret and refresh token, the source access token, and a signed JWT assertion to their own JSON-supplied token_uri or impersonation URL. Any caller that builds credentials from a configuration it does not fully control issues those requests from the application's network position, reaching hosts the configuration names, including internal services and link-local metadata endpoints, and hands them the credentials each request carries. The service_account assertion is bound to aud, so it is not replayable against Google. Version 0.06 added a _validate_url host check to the external_account class, keyed on a universe_domain read from the same credentials JSON. Version 0.07 gated a JSON-supplied universe domain behind GOOGLE_EXTERNAL_ACCOUNT_ALLOW_CUSTOM_UNIVERSES=1, deriving the pin flag from arguments that an earlier BUILDARGS pass had already merged on the make_creds path. Version 0.08 passed the pin decision through as an explicit constructor argument and moved _validate_url to Google::Auth::Credentials, adding the call to UserRefreshCredentials and ImpersonatedServiceAccountCredentials, and 0.09 added it to ServiceAccountCredentials.

References

NVD — CVE-2026-66901 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66901
Security Fix Commit FIX COMMIT
https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/9b5157062acc605ca9e6c507b910587f4829ce9e.patch
Security Fix Commit FIX COMMIT
https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/c95c77e70bec94f17e239d88050f843ea1cade95.patch
Security Fix Commit FIX COMMIT
https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/cbbb07804e3f8cc7cf9638ecc9c2097d80a9ef50.patch
Security Fix Commit FIX COMMIT
https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/cd42bdef53afcc4531161e85e91d0d5997e01324.patch
metacpan.org/release/cjcollier/g... WEB
https://metacpan.org/release/CJCOLLIER/Google-Auth-0.09/changes
Software Security Information SECURITY
http://www.openwall.com/lists/oss-security/2026/08/04/34

Frequently Asked Questions

What is CVE-2026-66901?
CVE-2026-66901 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-201: Insertion of Sensitive Information Into Sent Data.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-66901?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-66901?
CVE-2026-66901 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-66901?
CVE-2026-66901 is classified under CWE-201: Insertion of Sensitive Information Into Sent Data (The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.).
How can I check Maven dependencies for CVE-2026-66901?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xxpm-5c34-x4c3",
  "modified" : "2026-08-05T21:31:35Z",
  "published" : "2026-08-04T21:30:31Z",
  "aliases" : [ "CVE-2026-66901" ],
  "details" : "Google::Auth versions before 0.09 for Perl allow server side request forgery and credential exfiltration via unvalidated URLs taken from the credentials JSON.\n\nThe URLs the library requests are read from the credentials JSON, and their hosts were not checked against the universe domain before the request. For an external_account configuration, retrieve_subject_token fetched credential_source.url with headers from the same JSON, and fetch_access_token posted the subject token to token_url, then sent the STS access token it received to service_account_impersonation_url in an Authorization: Bearer header. The authorized_user, impersonated_service_account and service_account configurations posted the client secret and refresh token, the source access token, and a signed JWT assertion to their own JSON-supplied token_uri or impersonation URL.\n\nAny caller that builds credentials from a configuration it does not fully control issues those requests from the application's network position, reaching hosts the configuration names, including internal services and link-local metadata endpoints, and hands them the credentials each request carries. The service_account assertion is bound to aud, so it is not replayable against Google.\n\nVersion 0.06 added a _validate_url host check to the external_account class, keyed on a universe_domain read from the same credentials JSON. Version 0.07 gated a JSON-supplied universe domain behind GOOGLE_EXTERNAL_ACCOUNT_ALLOW_CUSTOM_UNIVERSES=1, deriving the pin flag from arguments that an earlier BUILDARGS pass had already merged on the make_creds path. Version 0.08 passed the pin decision through as an explicit constructor argument and moved _validate_url to Google::Auth::Credentials, adding the call to UserRefreshCredentials and ImpersonatedServiceAccountCredentials, and 0.09 added it to ServiceAccountCredentials.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-66901"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/9b5157062acc605ca9e6c507b910587f4829ce9e.patch"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/c95c77e70bec94f17e239d88050f843ea1cade95.patch"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/cbbb07804e3f8cc7cf9638ecc9c2097d80a9ef50.patch"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/cd42bdef53afcc4531161e85e91d0d5997e01324.patch"
  }, {
    "type" : "WEB",
    "url" : "https://metacpan.org/release/CJCOLLIER/Google-Auth-0.09/changes"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2026/08/04/34"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-201" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-04T21:16:37Z"
  }
}