How severe is CVE-2026-70492?

CVE-2026-70492 has a CVSS 3.x base score of 8.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-70492 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-70492?

CVE-2026-70492 affects Openwebui Open Webui. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-70492?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-70492 published?

CVE-2026-70492 was published on 2026-08-04 and last updated on 2026-09-18.

CVE-2026-70492

CVE-2026-70492 is a high-severity vulnerability in Openwebui Open Webui with a CVSS 3.x base score of 8.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: High (CVSS 3.x base score 8.7)
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Openwebui Open Webui
Published: 2026-08-04
Last modified: 2026-09-18

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.

Frequently asked questions

What is CVE-2026-70492?: 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.
How severe is CVE-2026-70492?: CVE-2026-70492 has a CVSS 3.x base score of 8.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-70492 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-70492?: CVE-2026-70492 affects Openwebui Open Webui. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-70492?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-70492 published?: CVE-2026-70492 was published on 2026-08-04 and last updated on 2026-09-18.

References

Affected products (1)

cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*

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