XSS in Cure53 Dompurify
CVE-2026-0540
DOMPurify 3.1.3 through 3.3.1 and 2.5.3 through 2.5.8, fixed in commit 2726c74, contain a cross-site scripting vulnerability that allows attackers to bypass attribute sanitization by exploiting five missing rawtext elements (noscript, xmp, noembed, noframes, iframe) in the SAFE_FOR_XML regex. Attackers can include payloads like </noscript><img src=x onerror=alert(1)> in attribute values to execute JavaScript when sanitized output is placed inside these unprotected rawtext contexts.
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 (24.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.9% 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
- Cure53 Dompurify — versions 3.1.3, 2.5.3
Weakness classification (CWE)
References
- github.com/cure53/DOMPurify (Product, product)
- github.com/cure53/DOMPurify/commit/302b51de22535cc90235472c52e3401bedd46f80 (patch)
- github.com/cure53/DOMPurify/releases/tag/3.3.2 (release-notes)
- fluidattacks.com/advisories/daft (third-party-advisory)
- www.vulncheck.com/advisories/dompurify-xss-via-missing-rawtext-elements-in-safe… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-0540?
- CVE-2026-0540 is a medium-severity vulnerability in Cure53 Dompurify, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-03.
- How severe is CVE-2026-0540?
- Medium severity. CVSS v3 base score is 6.1 out of 10.