Security context

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

expressjs/express

              master @ 18e5985
            

Fixes

CVEs

HIGH

Peak severity

65.6%

Coverage

Highlights

Denial of Service: 11 prior fixes. Scrutinize any change in this area.

lib/response.js: most-fixed (33 issues). Treat as high-risk during review.

14 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.

Open Redirect: The res.redirect and res.location APIs have repeatedly suffered from open redirect issues due to malformed URLs and backslash bypasses that manipulate host validation after encoding. This is also tracked under CVE-2024-29041.

Path Traversal: File serving APIs such as res.sendFile and res.download have historically failed to enforce strict root directory boundaries or correctly detect absolute paths across different operating systems, leading to arbitrary file read.

Reflected XSS: Response utilities previously allowed XSS by rendering untrusted URLs inside fallback anchor tags during redirects, failing to properly sanitize JSONP callback names, or omitting default UTF-8 character sets. This corresponds to CVE-2024-43796 and CVE-2014-6393.