Quick answers
- Is CVE-2026-109345 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-109345 being exploited in the wild.
- How severe is CVE-2026-109345?
- Medium severity, with a CVSS score of 6.1, published 12 October 2026.
- Which products and versions are affected?
- Cure53 DOMPurify before 3.4.16.
- Is there a fix for CVE-2026-109345?
- Yes: fixed in 3.4.16. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-109345 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-109345?
- Check whether you run Cure53 DOMPurify at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 3.4.16
Technical details
The vulnerability exists in DOMPurify's IN_PLACE sanitization mode when processing rawtext elements like <style>. While the _neutralizeSubtree function strips dangerous attributes from removed nodes, it does not sanitize text content, which can contain attacker-supplied markup. An attacker supplies a style element with text content like "</style><img src=x onerror=payload>" which bypasses the text-only sanitization check. Exploitation requires the application to serialize the returned node and re-parse it in HTML context.
Affected products
- Cure53 DOMPurify before 3.4.16
Timeline
- 2026-09-23: disclosed
- 2026-10-12: advisory