XSS in Kepano Defuddle
CVE-2026-30830
Defuddle cleans up HTML pages. Prior to version 0.9.0, the _findContentBySchemaText method in src/defuddle.ts interpolates image src and alt attributes directly into an HTML string without escaping. An attacker can use a " in the alt attribute to break out of the attribute context and inject event handler. This issue has been patched in version 0.9.0.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (18.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 18.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Kepano Defuddle — versions < 0.9.0
Weakness classification (CWE)
References
- github.com/kepano/defuddle/security/advisories/GHSA-5mq8-78gm-pjmq (Exploit, Mitigation, Vendor Advisory)
- github.com/kepano/defuddle/commit/f154cb740ee603431b69638273af737a27156df9 (Patch)
Frequently asked questions
- What is CVE-2026-30830?
- CVE-2026-30830 is a medium-severity vulnerability in Kepano Defuddle, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-07.
- How severe is CVE-2026-30830?
- Medium severity. CVSS v3 base score is 6.1 out of 10.