5.3 CVE-2026-34763

Enriched by CISA
 

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 stripping can fail and the generated directory listing may expose the full filesystem path in the HTML output. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
https://nvd.nist.gov/vuln/detail/CVE-2026-34763

Categories

CWE-625 : Permissive Regular Expression
The product uses a regular expression that does not sufficiently restrict the set of allowed values. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) When applicable, ensure that the regular expression marks beginning and ending string patterns, such as "/^string$/" for Perl. Chain: regex in EXIF processor code does not correctly determine where a string ends (CWE-625), enabling eval injection (CWE-95), as exploited in the wild per CISA KEV. ".*" regexp leads to static code injection insertion of username into regexp results in partial comparison, causing wrong database entry to be updated when one username is a substring of another. regexp intended to verify that all characters are legal, only checks that at least one is legal, enabling file inclusion. Regexp for IP address isn't anchored at the end, allowing appending of shell metacharacters. Regexp isn't "anchored" to the beginning or end, which allows spoofed values that have trusted values as substrings. regexp in .htaccess file allows access of files whose names contain certain substrings allow load of macro files whose names contain certain substrings.

References


 

AFFECTED (from MITRE)

Vendor Product Versions
rack rack
  • < 2.2.23 [affected]
  • >= 3.0.0.beta1, < 3.1.21 [affected]
  • >= 3.2.0, < 3.2.6 [affected]
© 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.

CPE

cpe start end

REMEDIATION


EXPLOITS

Exploit-db.com

id description date
No known exploits

POC Github

Url
No known exploits

Other Nist (github, ...)

Url
No known exploits

CAPEC

Common Attack Pattern Enumerations and Classifications

id description severity
No entry