Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-70492
open-webui open-webui — Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L L R C L L N 5.4 .0040 32.2 —
AFFECTED
Product Versions Fixed
open-webui >= 0.10.0, < 0.11.0 – —
TIMELINE
Aug 4 Reserved by GitHub_M
Aug 4 Published (CNA: GitHub_M)
Sep 18 EXPLOIT PUBLISHED — CVE-2026-70492 (open-webui). Public exploit reference added.
Sep 18 RESCORED — CVE-2026-70492 (open-webui). CVSS 8.7 → 5.4 (NVD).
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.
Lifecycle
Complete event history — 4 events, chronological
| Date | Event | Detail |
|---|
| August 4, 2026 | Reserved | Reserved by GitHub_M |
| August 4, 2026 | Published | Published (CNA: GitHub_M) |
| September 18, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-70492 (open-webui). Public exploit reference added. |
| September 18, 2026 | RESCORED | RESCORED — CVE-2026-70492 (open-webui). CVSS 8.7 → 5.4 (NVD). |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| open-webui | open-webui | — | >= 0.10.0, < 0.11.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-70492 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
