CVE-2026-49819

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Source
https://cve.org/CVERecord?id=CVE-2026-49819
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49819.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-49819
Aliases
  • GHSA-w4jr-728f-5jhq
Published
2026-08-12T23:13:46.298Z
Modified
2026-08-15T11:31:07.267830922Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
UpSnap - Unauthenticated Initial-Superuser Takeover Chains to Root RCE via wake_cmd
Details

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.

Database specific 
{
    "cwe_ids": [
        "CWE-269",
        "CWE-306",
        "CWE-78",
        "CWE-862"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49819.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/seriousm4x/upsnap

Affected ranges

Type
GIT
Repo
https://github.com/seriousm4x/upsnap
Events
Introduced
47b81553befa785b73ddc8aff2c6774975791ff2
Fixed
92f9e295d5f761d874a6701245b2e38dc42cb85a
Database specific
Show details 
{
    "source": "AFFECTED_FIELD",
    "extracted_events": [
        {
            "introduced": "4.4.1"
        },
        {
            "fixed": "5.4.0"
        }
    ]
}

Affected versions

4.*
4.4.1
4.4.2
4.4.2-beta.1
4.4.2-beta.2
4.5.0
4.5.1
4.6.0
5.*
5.0.0
5.0.0-beta.1
5.0.0-beta.2
5.0.0-beta.3
5.0.1
5.0.1-beta.1
5.0.1-beta.2
5.0.2
5.0.3
5.0.4
5.0.5
5.0.5-beta.1
5.0.6
5.0.7
5.0.8
5.1.0
5.1.1
5.1.10-beta.1
5.1.2
5.1.3
5.1.4
5.1.5
5.1.6
5.1.7
5.1.8
5.1.9
5.2.0
5.2.0-beta.0
5.2.0-beta.1
5.2.1
5.2.2
5.2.3
5.2.4
5.2.5
5.2.6
5.2.7
5.2.8
5.3.0
5.3.0-beta.0
5.3.1
5.3.2
5.3.2-beta.0
5.3.3
5.3.4
5.3.5

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49819.json"