CVE-2026-55374 is a medium-severity (CVSS 4.8) CWE-74 vulnerability in jleehr/canto-saas-api. A fix is available for jleehr/canto-saas-api — see the affected versions and patch details below.
canto-saas-api: Authenticated API requests can be redirected via unencoded path variables
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-55374.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
jleehr/canto-saas-apiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
In affected versions, Request::buildRequestUrl() inserts path variables into
the request URL without URL encoding (implode('/', $pathVariables)). All
request classes implementing getPathVariables() are affected, e.g.
GetContentDetailsRequest (scheme, contentId).
If a consuming application passes untrusted input (such as an ID taken from
an HTTP request parameter) as a path variable, characters like ../, ? or
# are sent verbatim and can change the path of the resulting API request.
Impact
An attacker who controls a path variable value can redirect the
library's authenticated request — the Bearer access token is attached in
AbstractEndpoint::sendRequest() — to a different API endpoint of the same
Canto instance, causing unintended reads or writes with the privileges of the
configured app. The impact depends on how the consuming application sources
path variable values; applications that only pass trusted, validated IDs are
not exploitable.
Patches
Fixed in 3.0.0: every path segment is encoded with rawurlencode() before
being inserted into the request URL.
Workarounds
If you cannot upgrade, validate untrusted values before passing them to
request classes, e.g. enforce an allowlist pattern such as
^[A-Za-z0-9_-]+$ for content IDs and schemes.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | jleehr/canto-saas-api | all versions | 3.0.0composer require jleehr/canto-saas-api:^3.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jleehr/canto-saas-api, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jleehr/canto-saas-api to 3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55374 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is CVE-2026-55374 in your dependencies?
Find it across Packagist, including transitive dependencies.