CVE-2026-39970

CVE-2026-39970 is a high-severity vulnerability with a CVSS 4.0 base score of 8.5. 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

Description

TypeBot is a chatbot builder tool. Versions 3.15.2 and prior contain a critical stored XSS vulnerability in the app.typebot.io profile picture upload form. The application fails to sanitize or restrict SVG/XML-based uploads and directly renders them when accessed through the domain. By uploading a crafted malicious SVG file containing embedded JavaScript, an attacker will execute arbitrary JavaScript code. This vulnerability directly enables stored XSS exploitation because the payload is persistently stored on your infrastructure (app.typebot.io) and accessible from a public-facing, permanent link. Stored XSS via malicious SVG uploads to app.typebot.io allows attackers to execute arbitrary JavaScript in victims' browsers, enabling session/token theft, account takeover, and exfiltration of sensitive user data. This issue has been fixed in version 3.16.0.

Frequently asked questions

What is CVE-2026-39970?
TypeBot is a chatbot builder tool. Versions 3.15.2 and prior contain a critical stored XSS vulnerability in the app.typebot.io profile picture upload form. The application fails to sanitize or restrict SVG/XML-based uploads and directly renders them when accessed through the domain. By uploading a crafted malicious SVG file containing embedded JavaScript, an attacker will execute arbitrary JavaScript code. This vulnerability directly enables stored XSS exploitation because the payload is persistently stored on your infrastructure (app.typebot.io) and accessible from a public-facing, permanent link. Stored XSS via malicious SVG uploads to app.typebot.io allows attackers to execute arbitrary JavaScript in victims' browsers, enabling session/token theft, account takeover, and exfiltration of sensitive user data. This issue has been fixed in version 3.16.0.
How severe is CVE-2026-39970?
CVE-2026-39970 has a CVSS 4.0 base score of 8.5, rated high severity.
Is CVE-2026-39970 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-39970?
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.
Does CVE-2026-39970 have an EU (EUVD) identifier?
Yes. CVE-2026-39970 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31478.
When was CVE-2026-39970 published?
CVE-2026-39970 was published on 2026-05-22 and last updated on 2026-06-17.

References

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

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