# 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.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-9qfv-wgh2-m6p8

## 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.

Weakness: CWE-918 (Server-Side Request Forgery), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2026-55374?

2 open source packages ship an affected version, including jleehr/canto-saas-api.


| Package | Ecosystem | 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.

## Is CVE-2026-55374 being exploited?

There is no known exploitation of CVE-2026-55374 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55374 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-55374 in the wild and no public exploit code.

Affected packages and fixed versions:
- jleehr/canto-saas-api (Packagist): affected all versions; fixed in 3.0.0
- jleehr/canto-saas-api (Packagist): affected all versions; fixed in 3.0.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55374/ (Markdown: https://insights.sbomify.com/CVE-2026-55374/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55374
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55374
- OSV: https://osv.dev/vulnerability/CVE-2026-55374

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55374/
Summaries are generated and may contain mistakes; the official description above is the record.