Vulnerability · Published Sep 15, 2026 · Assigned by GitHub_M
CVE-2026-55375canto-saas-api: OAuth credentials exposed in URL query string and exception messages
Medium 5.3
In plain English
A medium-severity security flaw in canto-saas-api from jleehr. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
canto-saas-api is a PHP library for interacting with the Canto SaaS API. Prior to version 3.0.0, OAuth2Request::getQueryParams() places app_id, app_secret, refresh_token, and code in the URL query string of token POST requests, allowing access logs, proxy logs, and APM traces to persist the credentials in plaintext. When a token request fails, OAuth2::obtainAccessToken() also passes the credential-bearing Guzzle request URI into AuthorizationFailedException, so application logs and error trackers can record the same secrets. An attacker with access to affected telemetry can obtain Canto credentials and use them to request access tokens for the tenant. This issue is fixed in version 3.0.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | jleehr/canto-saas-api | 3.0.0 | GHSA-37pm-83g7-r22v |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| jleehr | canto-saas-api | < 3.0.0 |
Weakness: CWE-209, CWE-598 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N