Highlights
Cross-Site Scripting (XSS): 5 prior fixes. Scrutinize any change in this area.
sanitize.go: most-fixed (4 issues). Treat as high-risk during review.
4 high-severity fixes 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): HTML sanitization bypasses occurred due to the tokenizer entering raw text mode when encountering tags like <script>, allowing subsequent payload injection to execute in the browser.
Cross-Site Scripting (XSS): The use of custom, regex-based sanitizers rather than structured, stateful parsers permitted complex HTML payloads to bypass the filter entirely, prompting a rewrite to an HTML5 tokenization strategy.
Cross-Site Scripting (XSS): The HTML renderer relied on a naive script-stripping regex that failed to neutralize robust payload variations, which was resolved by integrating an explicit tag allowlist pass.