{"id":"CVE-2026-59714","summary":"Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message_ids)","details":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 before 0.10.0, any authenticated user can overwrite the content of a message in a channel they do not belong to (including private and DM channels) by sending a chat completion request with a channel:-prefixed chat_id and a target message_id. The channel: path routes pipeline output through _make_channel_emitter, which writes to the Messages table using the caller-supplied message_id without binding it to the channel. This issue is fixed in version 0.10.0.","aliases":["GHSA-x2ff-v5v8-m75m","PYSEC-2026-3605"],"modified":"2026-08-16T03:31:19.870273627Z","published":"2026-08-13T19:10:42.122Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-862"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59714.json"},"references":[{"type":"WEB","url":"https://github.com/open-webui/open-webui/releases/tag/v0.10.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59714.json"},{"type":"ADVISORY","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-x2ff-v5v8-m75m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59714"},{"type":"FIX","url":"https://github.com/open-webui/open-webui/commit/ac3449cac91e62b08a7c28e54fcd044d14dea791"},{"type":"FIX","url":"https://github.com/open-webui/open-webui/pull/26385"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/open-webui/open-webui","events":[{"introduced":"3660bc00fd807deced3400a63bfa6db47811a3bb"},{"fixed":"4d2e13cf2bcc451b33bb6374bea4d2163e6cc94c"},{"fixed":"ac3449cac91e62b08a7c28e54fcd044d14dea791"}],"database_specific":{"extracted_events":[{"introduced":"0.9.5"},{"fixed":"0.10.0"}],"source":["DESCRIPTION","REFERENCES"]}}],"versions":["v0.9.5"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59714.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L"}]}