{"id":"CVE-2026-49819","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 \u003e 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.","aliases":["GHSA-w4jr-728f-5jhq"],"modified":"2026-08-15T11:31:07.267830922Z","published":"2026-08-12T23:13:46.298Z","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":[{"type":"WEB","url":"https://github.com/seriousm4x/UpSnap/releases/tag/5.4.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49819.json"},{"type":"ADVISORY","url":"https://github.com/seriousm4x/UpSnap/security/advisories/GHSA-w4jr-728f-5jhq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49819"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/seriousm4x/upsnap","events":[{"introduced":"47b81553befa785b73ddc8aff2c6774975791ff2"},{"fixed":"92f9e295d5f761d874a6701245b2e38dc42cb85a"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"4.4.1"},{"fixed":"5.4.0"}]}}],"versions":["5.3.5","5.3.4","5.3.3","5.3.2","5.3.2-beta.0","5.3.1","5.3.0","5.3.0-beta.0","5.2.8","5.2.7","5.2.6","5.2.5","5.2.4","5.2.3","5.2.2","5.2.1","5.2.0","5.2.0-beta.1","5.2.0-beta.0","5.1.10-beta.1","5.1.9","5.1.8","5.1.7","5.1.6","5.1.5","5.1.4","5.1.3","5.1.2","5.1.1","5.1.0","5.0.8","5.0.7","5.0.6","5.0.5","5.0.5-beta.1","5.0.4","5.0.3","5.0.2","5.0.1","5.0.1-beta.2","5.0.1-beta.1","5.0.0","5.0.0-beta.3","5.0.0-beta.2","5.0.0-beta.1","4.6.0","4.5.1","4.5.0","4.4.2","4.4.2-beta.2","4.4.2-beta.1","4.4.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49819.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}