GHSA-wqv2-4wpg-8hc9 Miniflux has an Open Redirect via protocol-relative redirect_url

• Go miniflux.app/v2: < 2.2.15 → fixed in 2.2.15

Summary `redirect_url` is treated as safe when `url.Parse(...).IsAbs()` is false. Protocol-relative URLs like `//ikotaslabs.com` have an empty scheme and pass that check, allowing post-login redirects to attacker-controlled sites. Details • `url.Parse("//ikotaslabs.com")` => empty Scheme, Host="ikotaslabs.com". • `IsAbs()` returns false for `//ikotaslabs.com`, so the code treats it as allowed. • Browser resolves `//ikotaslabs.com` to current-origin scheme (e.g. `https://ikotaslabs.com`), enabling phishing flows after login. PoC 1. Send or visit: `http://localhost/login?redirect_url=//ikotaslabs.com` 2. Complete normal login flow. 3. After login the app redirects to `https://ikotaslabs.com` (or `http://` depending on origin). Acknowledgements This vulnerability was discovered using the automated vulnerability analysis tools VulScribe and PwnML. The research and tool development were conducted with support from the MITOU Advanced Program (未踏アドバンスト事業), implemented by the Information-technology Promotion Agency (IPA), Japan.