0.0
NA
CVE-2026-66901
Google::Auth versions before 0.09 for Perl allow server side request forgery and credential exfiltration via unvalidated URLs taken from the credentials JSON
Description

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.

INFO

Published Date :

Aug. 4, 2026, 9:16 p.m.

Last Modified :

Aug. 4, 2026, 11:16 p.m.

Remotely Exploit :

No

Source :

9b29abf9-4ab0-4765-b253-1875cd9b441e
Affected Products

The following products are affected by CVE-2026-66901 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

Solution
Update Google::Auth for Perl to version 0.09 or later.
  • Update Google::Auth to version 0.09 or later.
  • Validate all external URLs.
  • Restrict access to sensitive endpoints.
  • Implement strict host validation.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-66901 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-66901 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-66901 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Aug. 04, 2026

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2026/08/04/34
  • New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e

    Aug. 04, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/GoogleCloudPlatform/google-auth-library-perl', 'vendor': 'CJCOLLIER', 'product': 'Google::Auth', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.09', 'versionType': 'custom'}], 'packageName': 'Google-Auth', 'programFiles': ['lib/Google/Auth/ExternalAccountCredentials.pm', 'lib/Google/Auth/ServiceAccountCredentials.pm', 'lib/Google/Auth/UserRefreshCredentials.pm', 'lib/Google/Auth/ImpersonatedServiceAccountCredentials.pm'], 'collectionURL': 'https://cpan.org/modules', 'defaultStatus': 'unaffected', 'programRoutines': [{'name': 'Google::Auth::ExternalAccountCredentials::retrieve_subject_token'}, {'name': 'Google::Auth::ExternalAccountCredentials::fetch_access_token'}, {'name': 'Google::Auth::ServiceAccountCredentials::fetch_access_token'}, {'name': 'Google::Auth::UserRefreshCredentials::fetch_access_token'}, {'name': 'Google::Auth::ImpersonatedServiceAccountCredentials::fetch_access_token'}]}]
    Added Description 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.
    Added CWE CWE-918
    Added CWE CWE-201
    Added Reference https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/9b5157062acc605ca9e6c507b910587f4829ce9e.patch
    Added Reference https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/c95c77e70bec94f17e239d88050f843ea1cade95.patch
    Added Reference https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/cbbb07804e3f8cc7cf9638ecc9c2097d80a9ef50.patch
    Added Reference https://github.com/GoogleCloudPlatform/google-auth-library-perl/commit/cd42bdef53afcc4531161e85e91d0d5997e01324.patch
    Added Reference https://metacpan.org/release/CJCOLLIER/Google-Auth-0.09/changes
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.