CVE-2026-28445
Because rating blocks are not flagged as isUnsafe by the import sanitizer and the builder preview renders bots inline on the builder's own origin (builder.typebot.io) under a CSP permitting 'unsafe-inline', a malicious imported or collaborator-crafted…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Typebot is a chatbot builder tool. In versions 3.15.2 and prior, the RatingButton component in the embed package renders the user-controlled customIcon.svg field directly via Solid's innerHTML directive without any sanitization, even though DOMPurify is already a dependency and is used elsewhere in the codebase (e.g., StreamingBubble.tsx). Because rating blocks are not flagged as isUnsafe by the import sanitizer and the builder preview renders bots inline on the builder's own origin (builder.typebot.io) under a CSP permitting 'unsafe-inline', a malicious imported or collaborator-crafted typebot can execute arbitrary HTML/JS in the builder's authenticated context, bypassing the Web Worker sandbox that protects Script blocks during preview. This allows session hijacking and privilege escalation within the builder application. This issue has been fixed in version 3.16.0.
- CVSS 3.1
- 8.7 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- EPSS
- 0.26% probability · 17th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- security-advisories@github.com
References
- https://github.com/baptisteArno/typebot.io/commit/474ecbf46bc47a75265bada2599f12b2179de375
- https://github.com/baptisteArno/typebot.io/releases/tag/v3.16.0
- https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-6m7c-xfhp-p9fh
- https://github.com/baptisteArno/typebot.io/security/advisories/GHSA-6m7c-xfhp-p9fh
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.