Highlights
HTTP Response Splitting: 1 prior fix. Scrutinize any change in this area.
Refit/RequestBuilderImplementation.cs: 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.
XXE: Default XML reader settings previously allowed DTD processing and external entity resolution, enabling XXE and entity-expansion attacks; fix prohibits DTD and clears resolver but may not cover all reader creation sites.
HTTP Response Splitting: CRLF injection via TryAddWithoutValidation allowed header injection and request smuggling; fix sanitizes CR/LF on this path, but other header-adding APIs or attribute processing may remain vulnerable.