{"id":"CVE-2026-105798","published":"2026-10-06T15:17:16.880","lastModified":"2026-10-06T15:25:00.650","description":"SimpleChat is a secure AI conversation application with personal and group workspaces for document-grounded interactions. Prior to 0.261.029, POST /api/group_documents/upload stores an attacker-controlled group document filename that group_workspaces.html later interpolates into inline Share event handlers. The escapeGroupHtml function leaves apostrophes unchanged, while escapeHtml produces an HTML entity that the browser decodes before JavaScript evaluation, so either path permits the filename to terminate the handler string. An authenticated group Owner, Admin, or DocumentManager can persist script that executes in the SimpleChat origin when another group member clicks Share, allowing access to victim-visible data and actions with the victim session. This issue is fixed in version 0.261.029.","cvssScore":8.7,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","cwes":["CWE-79"],"vendors":[],"products":[],"references":[{"url":"https://github.com/microsoft/simplechat/commit/537a259eb048b8f6d1c94193fa0c9683ab0bace9","tags":[]},{"url":"https://github.com/microsoft/simplechat/security/advisories/GHSA-qwcw-r653-j8c6","tags":[]},{"url":"https://github.com/microsoft/simplechat/security/advisories/GHSA-qwcw-r653-j8c6","tags":[]}],"exploitRefs":[{"url":"https://github.com/microsoft/simplechat/commit/537a259eb048b8f6d1c94193fa0c9683ab0bace9","tags":[]},{"url":"https://github.com/microsoft/simplechat/security/advisories/GHSA-qwcw-r653-j8c6","tags":[]},{"url":"https://github.com/microsoft/simplechat/security/advisories/GHSA-qwcw-r653-j8c6","tags":[]}],"hasPoc":true,"ai":{"summary":"The flaw allows an authenticated user to inject malicious script into group document filenames, which can be executed when another group member clicks a Share link, leading to potential data access and session hijacking.","exploitability":"Exploitation requires an authenticated user with Owner, Admin, or DocumentManager privileges in a specific group. The attacker must upload a malicious document filename.","blast_radius":"If exploited, the flaw could grant the attacker access to victim-visible data and actions within the victim's session, potentially leading to data theft or manipulation.","remediation":"Upgrade to version 0.261.029 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","auth-bypass","web"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-10-09T08:44:38.856Z"}}