CVE-2026-34831

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-2026-34763

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-2026-34785

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, 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...

CVE-2026-26961

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, 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...

CVE-2026-34230

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, 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 respon...

CVE-2026-34786

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, 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...

CVE-2026-34830

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-2026-34829

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, 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 transfe...

UBUNTU-CVE-2026-34831

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...

UBUNTU-CVE-2026-34826

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.getbyteranges parses the HTTP Range header without limiting the number of individual byte ranges. Although the existing fix for CVE-2024-26141 rejects ranges whose total byte coverage exceeds the...

UBUNTU-CVE-2026-34786

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, 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...

CVE-2026-26962 Rack: Header injection in multipart requests

Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename o...

CVE-2026-26962 Rack: Header injection in multipart requests

Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename o...

CVE-2026-26962

Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename o...

CVE-2026-26962

Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename o...

CVE-2026-26962 Rack: Header injection in multipart requests

Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename o...

CVE-2026-26962

Summary : Rack (Ruby web server interface) versions 3.2.0–3.2.5 are affected by a header unfolding issue in Rack::Multipart::Parser. When a multipart header includes an obs-fold sequence, the parser preserves the embedded CRLF in parsed parameter values (e.g., filename or name) during unfolding, ...

CVE-2026-34835

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...

CVE-2026-34835 Rack: `Rack::Request` accepts invalid Host characters, enabling host allowlist bypass.

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...

CVE-2026-34835 Rack: `Rack::Request` accepts invalid Host characters, enabling host allowlist bypass.

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...