CVE-2026-7808
CriticalCVSS 9.8Summary
justhtml before 1.16.0 contains multiple HTML sanitization bypass issues that can allow active/dangerous content (e.g., script or style) to survive sanitization, potentially leading to XSS. The issues primarily affect advanced usage rather than the default JustHTML(..., sanitize=True) path.
Risk Assessment
The organization may be exposed to XSS if using advanced justhtml features such as mutating sanitization policy objects, programmatic DOM, or custom policies for SVG/MathML. An attacker can inject active content that executes in the browser.
Recommendation
Update justhtml to version 1.16.0 or later. Avoid modifying default policy objects and use the default sanitize=True configuration when possible.
Original NVD description (English source)
justhtml before 1.16.0 contains multiple HTML sanitization bypass issues that can allow active/dangerous content (e.g., script or style) to survive sanitization, potentially leading to cross-site scripting. The issues primarily affect advanced usage rather than the default JustHTML(..., sanitize=True) path for ordinary parsed HTML: mutating or reusing sanitization policy objects (including exported defaults) could weaken later sanitization; programmatic DOM input to sanitize()/sanitize_dom() could miss mixed-case tag names (e.g., ScRiPt, StYlE); crafted programmatic doctype names could serialize into active markup; and custom policies preserving SVG or MathML could allow animation elements, presentation attributes with external url(...) references, or DOM trees mislabeled as namespace="html" to bypass foreign-content checks. Fixed in 1.16.0.