{"id":"CVE-2026-49819","aliases":["EUVD-2026-57697","GHSA-w4jr-728f-5jhq"],"status":"published","title":"UpSnap - Unauthenticated Initial-Superuser Takeover Chains to Root RCE via wake_cmd","description":"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.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.0108,"percentile":0.65392,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-269","CWE-306","CWE-78","CWE-862"],"published":"2026-08-12T23:13:46Z","modified":"2026-10-28T02:30:27Z","products":[{"vendor":"seriousm4x","product":"upsnap"}],"references":[{"url":"https://github.com/seriousm4x/UpSnap/security/advisories/GHSA-w4jr-728f-5jhq","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/seriousm4x/UpSnap/releases/tag/5.4.0","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49819.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49819","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-49819","title":"UpSnap - Unauthenticated Initial-Superuser Takeover Chains to Root RCE via wake_cmd","description":"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.","status":"published","published":"2026-08-12T23:13:46.298Z","modified":"2026-08-13T13:08:59.003Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-78","CWE-269","CWE-306","CWE-862"],"updated_at":"2026-11-02T13:34:59.78118Z"}],"euvd":[{"id":"EUVD-2026-57697","description":"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.","status":"published","published":"2026-08-12T23:13:46Z","modified":"2026-08-13T13:08:59Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T18:01:56.761721Z"}],"nvd":[{"id":"CVE-2026-49819","description":"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.","status":"published","published":"2026-08-13T00:17:32.747Z","modified":"2026-10-24T16:10:00.153Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-78","CWE-269","CWE-306","CWE-862"],"updated_at":"2026-11-02T14:12:37.217486Z"}],"osv":[{"id":"CVE-2026-49819","title":"UpSnap - Unauthenticated Initial-Superuser Takeover Chains to Root RCE via wake_cmd","description":"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.","status":"published","published":"2026-08-12T23:13:46.298Z","modified":"2026-10-28T02:30:27.087090242Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-269","CWE-306","CWE-78","CWE-862"],"updated_at":"2026-11-02T15:45:07.060148Z"}]}}