CVE-2026-84315

Reporter: Jagadesh Achanta Target: `0xJacky/nginx-ui` Affected version / commit tested: - App version: `2.3.10` - Commit: `4948fba8744e82c3d7003f68ee164e9f49421066` - Disclosure channel: GitHub Private Vulnerability Reporting - Credential reference: `cred:github-jagstack-gh-cli` ## AI assistance disclosure This report was prepared by Jagadesh Achanta with assistance from OpenAI/Codex for public source review, local evidence collection, and report drafting. ## Summary Nginx UI has a short-lived OTP/passkey "secure session" step-up boundary for users with 2FA enabled. `RequireSecureSession()` rejects an OTP-enabled user's request unless the request includes a valid `X-Secure-Session-ID` issued after a fresh OTP/passkey verification. The project already applies this step-up middleware to sensitive operations such as: - Nginx config create/edit/rename/delete; - site save/delete/enable/disable/rename/duplicate; - stream save/delete/enable/disable/rename/duplicate; - settings save and protected secret reads; - backup restore. However, several similarly sensitive authenticated mutation routes remain outside `RequireSecureSession()`. An attacker who obtains an authenticated JWT/session for a 2FA-enabled user, but does not have the victim's fresh OTP/passkey secure-session token, can still perform those operations. The affected route groups include: - automatic backup create/modify/delete/restore/test-S3 operations; - DNS credential create/edit/delete operations; - certificate and ACME user create/modify/delete/register operations; - DNS domain, record, and DDNS create/update/delete operations; - Nginx reload/restart, stub-status toggle, performance-setting update, and module-cache refresh operations; - site/stream advanced-mode toggles and batch updates; - auto-certificate binding/unbinding for sites; - site navigation order and health-check updates. This report is distinct from my earlier Nginx UI report about auto-backup path traversal. This report is about mi