CVE-2026-55374 canto-saas-api: Authenticated API requests can be redirected via unencoded path variables
Attackers can manipulate unencoded path variables to redirect authenticated API requests, enabling unauthorized data access or modification on the Canto instance.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55374?
CVE-2026-55374 is a medium-severity server-side request forgery vulnerability in jleehr canto-saas-api, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, 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, Request::buildRequestUrl() joins values returned by Request::getPathVariables() without encoding individual path segments, including the scheme and contentId values used by GetContentDetailsRequest. When a consuming application supplies an untrusted path variable value, path traversal sequences, query delimiters, or fragment delimiters can change the destination endpoint before AbstractEndpoint::sendRequest() attaches the configured authentication token. An attacker who controls that path variable value through the consuming application can cause unintended reads or writes with the configured application's privileges on the same Canto instance, but applications that pass only trusted and validated identifiers are not exploitable. This issue is fixed in version 3.0.0.
Which versions are affected by CVE-2026-55374?
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-2026-55374?
Upgrade jleehr/canto-saas-api to 3.0.0 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-55374 being exploited?
There is no known exploitation of CVE-2026-55374 in the wild and no public exploit code.
Sources
Also known as GHSA-9qfv-wgh2-m6p8.