CVE-2026-49819 json
UpSnap - Unauthenticated Initial-Superuser Takeover Chains to Root RCE via wake_cmd
published 2026-08-12 2 mo ago modified 2026-10-24 15 d ago also EUVD-2026-57697
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 65%
- public exploits
- 0
- none known
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.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- total
- Assessed
- 2 mo ago
Exploit prediction
1.08% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/seriousm4x/UpSnap/security/advisories/GHSA-w4jr-728f-5jhq referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- seriousm4x UpSnap
Classification
References
Sources
- CVE List CVE-2026-49819
- NVD CVE-2026-49819
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