CVE-2026-34830: Permissive Regular Expression

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Sendfilemapaccelpath interpolates the value of the X-Accel-Mapping request header directly into a regular expression when rewriting file paths for X-Accel-Redirect. Because the header value is not...

CVE-2026-34831: Improper Handling of Length Parameter Inconsistency

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Filesfail sets the Content-Length response header using Stringsize instead of Stringbytesize. When the response body contains multibyte UTF-8 characters, the declared Content-Length is smaller than the...

CVE-2026-34835: Improper Validation of Syntactic Correctness of Input

Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21, and 3.2.0 to before 3.2.6, Rack::Request parses the Host header using an AUTHORITY regular expression that accepts characters not permitted in RFC-compliant hostnames, including /, ?, , and @. Because req.hos...

Rack 安全漏洞

Rack is a modular Ruby web server interface developed by Rack authors. Vulnerabilities exist in versions of Rack prior to 2.2.23, 3.1.21, and 3.2.6. These vulnerabilities stem from the use of Stringsize instead of Stringbytesize to set the Content-Length response header in Rack::Filesfail, which...

Rack 信息泄露漏洞

Rack is a modular Ruby web server interface developed by Rack authors. Versions of Rack prior to 2.2.23, 3.1.21, and 3.2.6 contained an information leakage vulnerability. This vulnerability stemmed from Rack::Static’s use of simple string prefix checks to determine whether a request should be...

Rack 安全漏洞

Rack is a modular Ruby web server interface developed by the Rack open-source project. Versions of Rack prior to 2.2.23, 3.1.21, and 3.2.6 contained security vulnerabilities. These vulnerabilities stemmed from Rack::Directory allowing the root path of configuration settings to be directly inserte...

Rack 安全漏洞

Rack is a modular Ruby web server interface developed by the Rack open-source project. Versions of Rack prior to 2.2.23, 3.1.21, and 3.2.6 contained security vulnerabilities. These vulnerabilities stemmed from the use of greedy regular expressions by the multipart parser to extract boundary...

Rack 安全漏洞

Rack is a modular Ruby web server interface developed by Rack authors. Versions of Rack prior to 3.1.21 and 3.2.6 contained security vulnerabilities. These vulnerabilities stemmed from the use of the AUTHORITY regular expression for parsing Host headers in Rack::Request, allowing illegal characte...

Rack 安全漏洞

Rack is a modular Ruby web server interface developed by Rack authors. Versions of Rack prior to 3.1.21 and 3.2.6 contained security vulnerabilities. These vulnerabilities stemmed from improper handling of multi-part parameters with quotes during the parsing of...

CVE-2026-34763: Permissive Regular Expression

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Directory interpolates the configured root path directly into a regular expression when deriving the displayed directory path. If root contains regex metacharacters such as +, , or ., the prefix...

CVE-2026-32762: Interpretation Conflict

Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21 and 3.2.0 to before 3.2.6, Rack::Utils.forwardedvalues parses the RFC 7239 Forwarded header by splitting on semicolons before handling quoted-string values. Because quoted values may legally contain semicolons...

Rack:: Static header_rules bypass via URL-encoded paths

Summary Rack::Staticapplicablerules evaluates several headerrules types against the raw URL-encoded PATHINFO, while the underlying file-serving path is decoded before the file is served. As a result, a request for a URL-encoded variant of a static path can serve the same file without the headers...

Rack has Content-Length mismatch in Rack::Files error responses

Summary Rack::Filesfail sets the Content-Length response header using Stringsize instead of Stringbytesize. When the response body contains multibyte UTF-8 characters, the declared Content-Length is smaller than the number of bytes actually sent on the wire. Because Rack::Files reflects the...

Rack - Forwarded Header semicolon injection enables Host and Scheme spoofing

Summary Rack::Utils.forwardedvalues parses the RFC 7239 Forwarded header by splitting on semicolons before handling quoted-string values. Because quoted values may legally contain semicolons, a header such as: http Forwarded: for="127.0.0.1;host=evil.com;proto=https" can be interpreted by Rack as...

Rack::Static prefix matching can expose unintended files under the static root

Summary Rack::Static determines whether a request should be served as a static file using a simple string prefix check. When configured with URL prefixes such as "/css", it matches any request path that begins with that string, including unrelated paths such as "/css-config.env" or...

Rack's multipart header parsing allows Denial of Service via escape-heavy quoted parameters

Summary Rack::Multipart::Parserhandlemimehead parses quoted multipart parameters such as Content-Disposition: form-data; name="..." using repeated Stringindex searches combined with Stringslice! prefix deletion. For escape-heavy quoted values, this causes super-linear processing. An unauthenticat...

Rack::Sendfile header-based X-Accel-Mapping regex injection enables unauthorized X-Accel-Redirect

Summary Rack::Sendfilemapaccelpath interpolates the value of the X-Accel-Mapping request header directly into a regular expression when rewriting file paths for X-Accel-Redirect. Because the header value is not escaped, an attacker who can supply X-Accel-Mapping to the backend can inject regex...

Rack's multipart parsing without Content-Length header allows unbounded chunked file uploads

Summary Rack::Multipart::Parser only wraps the request body in a BoundedIO when CONTENTLENGTH is present. When a multipart/form-data request is sent without a Content-Length header, such as with HTTP chunked transfer encoding, multipart parsing continues until end-of-stream with no total size...

Rack has quadratic complexity in Rack::Utils.select_best_encoding via wildcard Accept-Encoding header

Summary Rack::Utils.selectbestencoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard entries. Because this method is used by Rack::Deflater to choose a response encoding, an unauthenticated attacker can send a single request with a crafted...

Rack's greedy multipart boundary parsing can cause parser differentials and WAF bypass.

Summary Rack::Multipart::Parser extracts the boundary parameter from multipart/form-data using a greedy regular expression. When a Content-Type header contains multiple boundary parameters, Rack selects the last one rather than the first. In deployments where an upstream proxy, WAF, or intermedia...