{"cve":"CVE-2026-28788","nvd":{"published":"2026-03-27T00:16:22.673","modified":"2026-06-17T10:29:02.773","status":"Analyzed","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.8.6, any authenticated user can overwrite any file's content by ID through the `POST /api/v1/retrieval/process/files/batch` endpoint. The endpoint performs no ownership check, so a regular user with read access to a shared knowledge base can obtain file UUIDs via `GET /api/v1/knowledge/{id}/files` and then overwrite those files, escalating from read to write. The overwritten content is served to the LLM via RAG, meaning the attacker controls what the model tells other users. Version 0.8.6 patches the issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L","score":7.1},"cwes":["CWE-639"],"references":["https://github.com/open-webui/open-webui/security/advisories/GHSA-jjp7-g2jw-wh3j"],"products":["openwebui:open_webui"],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-28788","score":0.02969,"percentile":0.87239,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-jjp7-g2jw-wh3j","url":"https://osv.dev/vulnerability/GHSA-jjp7-g2jw-wh3j","summary":"Open WebUI's process_files_batch() endpoint missing ownership check, allows unauthorized file overwrite","modified":"2026-07-13T16:42:38.388018547Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.8.6"],"fixed":["0.8.6"]}]},{"id":"PYSEC-2026-2742","url":"https://osv.dev/vulnerability/PYSEC-2026-2742","summary":"Open WebUI's process_files_batch() endpoint missing ownership check, allows unauthorized file overwrite","modified":"2026-07-13T16:32:21.044789378Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.8.6"],"fixed":["0.8.6"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}