Users providing user generated input into the resolveEndpoint method on requests.
Upgrade to Saloon v4+
Upgrade guide: https://docs.saloon.dev/upgrade/upgrading-from-v3-to-v4
When building the request URL, Saloon combined the connector's base URL with the request endpoint. If the endpoint was a valid absolute URL (e.g. https://attacker.example.com/callback), the code used that URL as-is and ignored the base URL. The request—and any authentication headers, cookies, or tokens attached by the connector—was then sent to the attacker-controlled host. If the endpoint could be influenced by user input or configuration (e.g. redirect_uri, callback URL), this allowed server-side request forgery (SSRF) and/or credential leakage to a third-party host. The fix (in the next major version) is to reject absolute URLs in the endpoint: URLHelper::join() throws InvalidArgumentException when the endpoint is a valid absolute URL, unless explicitly allowed, requiring callers to opt-in to the functionality on a per-connector or per-request basis.
Saloon thanks @HuajiHD for finding the issue and recommending solutions and @JonPurvis for applying the fix.
| Score | Percentile |
|---|---|
| 0.03% | 7.79% |
| Base score | Version | Severity | Vector |
|---|---|---|---|
| 6.6 | 4.0 | — |
|
| Type | Value |
|---|---|
| GHSA | GHSA-c83f-3xp6-hfcp ↗ |
| CVE | CVE-2026-33182 ↗ |
Vulnerable version ranges and first patched releases as published by GitHub.
| Ecosystem | Package | Vulnerable range | First patched | Vulnerable functions |
|---|---|---|---|---|
| composer | saloonphp/saloon | < 4.0.0 | 4.0.0 | — |