CVE-2026-55375 canto-saas-api: OAuth credentials exposed in URL query string and exception messages
An attacker with access to logs or traces can steal OAuth credentials exposed in URLs and exceptions, allowing them to obtain access tokens for the tenant.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55375?
CVE-2026-55375 is a medium-severity vulnerability in jleehr canto-saas-api, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Which versions are affected by CVE-2026-55375?
2 open source packages ship an affected version, including jleehr/canto-saas-api.
| Package | Affected | Fixed in |
|---|---|---|
jleehr/canto-saas-api Packagist | All versions | 3.0.0 |
jleehr/canto-saas-api Packagist | All versions | 3.0.0 |
How do I fix CVE-2026-55375?
Upgrade jleehr/canto-saas-api to 3.0.0 or later.
Is CVE-2026-55375 being exploited?
There is no known exploitation of CVE-2026-55375 in the wild and no public exploit code.
Sources
Also known as GHSA-37pm-83g7-r22v.