{"id":"CVE-2026-70492","published":"2026-08-04T21:16:38.190","lastModified":"2026-08-05T16:17:02.890","description":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.0, src/lib/components/chat/Messages/Markdown/KatexRenderer.svelte could store and render a chat message whose math block makes KaTeX fail with a stack overflow instead of a parse error. The catch branch fell back to inserting the original math source into the page as HTML through {@html} rather than as text, so script in the message runs in the browser of whoever views it, including shared chats and channels. The viewer's session token in localStorage can be stolen, and an administrator viewer can have their account taken over. This issue is fixed in 0.11.0.","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/open-webui/open-webui/commit/bc600d3f085802c45aa8f38c30e6e8c986bde6cc","tags":[]},{"url":"https://github.com/open-webui/open-webui/pull/26718","tags":[]},{"url":"https://github.com/open-webui/open-webui/releases/tag/v0.11.0","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x","tags":[]}],"exploitRefs":[{"url":"https://github.com/open-webui/open-webui/commit/bc600d3f085802c45aa8f38c30e6e8c986bde6cc","tags":[]},{"url":"https://github.com/open-webui/open-webui/pull/26718","tags":[]},{"url":"https://github.com/open-webui/open-webui/releases/tag/v0.11.0","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x","tags":[]}],"hasPoc":true,"ai":{"summary":"A flaw in Open WebUI allowed math blocks to cause a stack overflow, rendering them as executable HTML, leading to potential session token theft and account takeover.","exploitability":"Exploitation requires viewing a malicious chat message; preconditions include the target being part of a shared chat or channel.","blast_radius":"The impact is significant if exploited, potentially compromising multiple users' sessions in shared environments.","remediation":"Update to Open WebUI version 0.11.0 immediately to mitigate this vulnerability.","tags":["rce","web","auth-bypass","html-execution","chat"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-08-11T06:47:59.953Z"}}