{"id":"CVE-2026-109284","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","summary":"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 …","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-862"],"published":"2026-10-12","updated":"2026-10-12","sourceUpdated":"2026-10-12T17:17:21.317","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-109284","references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-6fjc-5cg3-mgvh","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/open-webui-0.11.0-before-0.11.4-improper-authorization-via-chat-fork-endpoint","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"ingestedAt":"2026-10-12T18:00:08.188Z","slug":"CVE-2026-109284","body":"## Overview\n\nOpen 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}