Security context

What an agent needs to avoid regressing past fixes and find the next vuln in this repo.

nahsra/antisamy

              main @ 0b0e4dc
            

Fixes

CVEs

HIGH

Peak severity

Highlights

Cross-Site Scripting (XSS): 1 prior fix. Scrutinize any change in this area.

src/main/java/org/owasp/validator/css/CssValidator.java: most-fixed (1 issue). Treat as high-risk during review.

1 high-severity fix in this history; regressions here are high-impact.

Recurring patterns

The bug types that recur here, drawn from past fixes, not open vulnerabilities.

Cross-Site Scripting (XSS): Attackers can bypass stylesheet sanitization by smuggling malicious 'javascript:' URIs within CSS lexical units, string identifiers, and fallback values. This requires strict validation and blocklisting of URI formats during lexical analysis.

XSS: Flaws in attribute indexing and filter structures can result in duplicated or missed attribute sanitization (such as duplicate 'rel' attributes), creating a pathway for parser-differential bypasses.

Cross-Site Scripting (XSS): Mutation XSS risks occur when 'preserveComments' is enabled in the policy, allowing malformed HTML comments or tags to change shape and execute script when parsed by the browser.