CVE-2026-49819
UpSnap - Unauthenticated Initial-Superuser Takeover Chains to Root RCE via wake_cmd
UpSnap is a wake on lan web app. Versions 4.4.1 through 5.3.5 are vulnerable to a missing-authentication / privilege-escalation chain in `pb.HandlerInitSuperuser` (`backend/pb/handlers.go:249`), reachable as `POST /api/upsnap/init-superuser`. The vulnerable code lacks any authentication, setup token, IP allow-list, or rate limit and is gated only by a `totalSuperusers > 0` count check — a condition that is false on every fresh install — allowing an unauthenticated network-adjacent attacker to register the initial superuser account, receive a long-lived JWT, and pivot to root remote code execution at `backend/networking/wake.go:43` (`exec.CommandContext(ctx, "/bin/sh", "-c", wake_cmd)`). Version 5.4.0 fixes the issue.
| CWE | CWE-78 CWE-269 CWE-306 CWE-862 |
| Vendor | seriousm4x |
| Product | upsnap |
| Published | Aug 12, 2026 |
Get instant alerts for seriousm4x upsnap
Be the first to know when new critical vulnerabilities affecting seriousm4x upsnap are published — delivered to Slack, Telegram or Discord.
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H