Ruby vulnerabilities
We track 15 vulnerabilities in Ruby products across 8 products. 15 are rated high or critical, and none are known to be exploited. The most recent was published on August 27, 2026.
Latest Ruby vulnerabilities
- 7.5 High severity
resolv: Allocation of Resources Without Limits or Throttling
An issue was discovered in the resolv gem before 0.7.2 for Ruby. Resolv::DNS::Resource.get_class, Resolv::DNS::Resource::Generic.create, and Resolv::DNS::SvcParam::Generic.create generate a new class for each unknown DNS resource record (type, class) pair, or
- 8.7 High severity
json: Use After Free
Ruby JSON is a JSON implementation for Ruby. From 2.20.0 until 2.21.2, Ruby's JSON native C extension clears the consumed JSON::ResumableParser input buffer but leaves state.start, state.cursor, and state.end pointing into released storage. When partial_value
- 9.8 Critical severity
net-imap: Improper Neutralization of Special Elements used in a Command
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, several Net::IMAP commands accept a raw string argument that is sent to the server without validation or escaping. If this s
- 7.4 High severity
net-imap: Missing Report of Error Condition
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAP#starttls to return "successfully", without starting TLS. This issue
- 7.5 High severity
net-imap: Inefficient Algorithmic Complexity
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, Net::IMAP::ResponseReader has quadratic time complexity when reading large responses containing many string literals. A host
- 8.1 High severity
erb: Protection Mechanism Failure
ERB is a templating system for Ruby. Ruby 2.7.0 (before ERB 2.2.0 was published on rubygems.org) introduced an `@_init` instance variable guard in `ERB#result` and `ERB#run` to prevent code execution when an ERB object is reconstructed via `Marshal.load` (dese
- 9.8 Critical severity
zlib: Buffer Copy without Checking Size of Input
zlib is a Ruby interface for the zlib compression/decompression library. Versions 3.0.0 and below, 3.1.0, 3.1.1, 3.2.0 and 3.2.1 contain a buffer overflow vulnerability in the Zlib::GzipReader. The zstream_buffer_ungets function prepends caller-provided bytes
- 9.1 Critical severity
json: Use of Externally-Controlled Format String
Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerability can lead to denial of service attacks or information disclosure, when the allow_duplicate_key: false par
- 7.5 High severity
uri: Exposure of Sensitive Information to an Unauthorized Actor
URI is a module providing classes to handle Uniform Resource Identifiers. In versions 0.12.4 and earlier (bundled in Ruby 3.2 series) 0.13.2 and earlier (bundled in Ruby 3.3 series), 1.0.3 and earlier (bundled in Ruby 3.4 series), when using the + operator to
- 7.5 High severity
resolv: Uncontrolled Resource Consumption
The attack vector is a potential Denial of Service (DoS). The vulnerability is caused by an insufficient check on the length of a decompressed domain name within a DNS packet. An attacker can craft a malicious DNS packet containing a highly compressed domain n
- 7.5 High severity
json: Out-of-bounds Read
JSON is a JSON implementation for Ruby. Starting in version 2.10.0 and prior to version 2.10.2, a specially crafted document could cause an out of bound read, most likely resulting in a crash. Versions prior to 2.10.0 are not vulnerable. Version 2.10.2 fixes t
- 7.5 High severity
rexml: Inefficient Regular Expression Complexity
REXML is an XML toolkit for Ruby. The REXML gem before 3.3.9 has a ReDoS vulnerability when it parses an XML that has many digits between &# and x...; in a hex numeric character reference (&#x...;). This does not happen with Ruby 3.2 or later. Ruby 3.1 is the
- 7.5 High severity
rexml: Uncontrolled Resource Consumption
REXML is an XML toolkit for Ruby. The REXML gem 3.3.2 has a DoS vulnerability when it parses an XML that has many entity expansions with SAX2 or pull parser API. The REXML gem 3.3.3 or later include the patch to fix the vulnerability.
- 7.5 High severity
rexml: Uncontrolled Resource Consumption
REXML is an XML toolkit for Ruby. The REXML gem before 3.3.2 has some DoS vulnerabilities when it parses an XML that has many specific characters such as whitespace character, `>]` and `]>`. The REXML gem 3.3.3 or later include the patches to fix these vulnera
- 7.1 High severity
phlex: Improper Neutralization of Input During Web Page Generation
phlex is an open source framework for building object-oriented views in Ruby. There is a potential cross-site scripting (XSS) vulnerability that can be exploited via maliciously crafted user data. The filter to detect and prevent the use of the `javascript:` U