CVE-2026-49819 (GCVE-0-2026-49819)
Vulnerability from cvelistv5 – Published: 2026-08-12 23:13 – Updated: 2026-08-13 13:08
VLAI
EPSS
VEX
Title
UpSnap - Unauthenticated Initial-Superuser Takeover Chains to Root RCE via wake_cmd
Summary
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.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-13 13:08 UTC
CWE
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/seriousm4x/UpSnap/security/adv… | x_refsource_CONFIRM |
| https://github.com/seriousm4x/UpSnap/releases/tag/5.4.0 | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| seriousm4x | UpSnap |
Affected:
>= 4.4.1, < 5.4.0
|
guessed |
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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