CVE-2026-39970Public exploitNetwork attack vector

Stored XSS via unsanitized SVG avatar uploads

Published May 22, 2026 · Updated May 22, 2026

Stored XSS in Typebot before 3.16.0 allows remote authenticated users to execute JavaScript through a crafted profile-picture SVG. The profile-picture upload accepts SVG/XML content without sanitizing or restricting active markup, stores it publicly, and serves it for direct browser rendering. A low-privilege account must upload the file and a victim must open its permanent link, exposing browser-accessible session data and actions.

CVSS severity8.5
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Typebot before 3.16.0 allows remote authenticated users to execute JavaScript through a crafted profile-picture SVG. The profile-picture upload accepts SVG/XML content without sanitizing or restricting active markup, stores it publicly, and serves it for direct browser rendering. A low-privilege account must upload the file and a victim must open its permanent link, exposing browser-accessible session data and actions.

The record

CVE
CVE-2026-39970
Published
May 22, 2026
Updated
May 22, 2026
Vendor
Typebot
Product
Typebot
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 2026CVE publishedPublication date reported by the CVE source.
  2. May 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.16.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Typebot · Typebotversion=< 3.16.0

Published CVSS scores

8.5GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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