{"id":"CVE-2026-49819","title":"UpSnap is a wake on lan web app","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-superu…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-78","CWE-269","CWE-306","CWE-862"],"vendor":"seriousm4x","product":"UpSnap","affected":["UpSnap >= 4.4.1, < 5.4.0"],"published":"2026-08-13","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:02:22.660","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-49819","references":[{"url":"https://github.com/seriousm4x/UpSnap/releases/tag/5.4.0","label":"security-advisories@github.com"},{"url":"https://github.com/seriousm4x/UpSnap/security/advisories/GHSA-w4jr-728f-5jhq","label":"security-advisories@github.com"},{"url":"https://github.com/seriousm4x/UpSnap/security/advisories/GHSA-w4jr-728f-5jhq","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","cve.org","exploit-available"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"total","timestamp":"2026-08-13T13:08:41.648461Z"},"ingestedAt":"2026-09-13T14:51:45.950Z","epss":0.00792,"epssPercentile":0.54793,"slug":"CVE-2026-49819","body":"## Overview\n\nUpSnap 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"abyssal","depthScore":66,"depthScoreParts":{"impact":53.9,"likelihood":0.2,"exploitation":12,"ransomware":0},"changes":[]}