CVE-2026-55374 is a medium-severity (CVSS 4.8) CWE-74 vulnerability in jleehr/canto-saas-api. O3 Security confirms whether CVE-2026-55374 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
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.
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
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | jleehr/canto-saas-api | all versions | 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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55374 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55374. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55374 in your dependencies?
O3 detects CVE-2026-55374 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.