{"id":"CVE-2026-109284","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-109284","generatedAt":"2026-10-28T01:03:08.940Z","title":"Open WebUI from 0.11.0 before 0.11.4 contains an improper authorization vulnerability in the chat fork handler, which places forked chats in the source chat's folder without checking folder write access.","description":"Open WebUI from 0.11.0 before 0.11.4 contains an improper authorization vulnerability in the chat fork handler, which places forked chats in the source chat's folder without checking folder write access. Shared folder members downgraded to read-only can call POST /api/v1/chats/{id}/fork on chats they created there while they had write access, inserting attacker-controlled chats visible to the folder owner and members.","published":"2026-10-12T17:17:21.000Z","lastModified":"2026-10-13T20:39:49.000Z","status":"Awaiting Analysis","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":5.3,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-862"],"affected":[],"epss":{"score":0.00209,"percentile":0.11018,"date":"2026-10-26","history":[{"date":"2026-10-13","score":0.00209,"percentile":0.10332}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-12T17:17:21.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-10-12T17:17:21.317Z"},"summary":"New CVE, medium severity (CVSS 5.3)."}],"references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-6fjc-5cg3-mgvh","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/open-webui-0.11.0-before-0.11.4-improper-authorization-via-chat-fork-endpoint","source":"disclosure@vulncheck.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-109284","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}