GitLab Community Edition and Enterprise Edition contain a integer overflow or wraparound vulnerability that could allow an unauthenticated user to execute arbitrary code on the GitLab server via a specially crafted regular expression in a CI/CD configuration, due to insufficient regular expression validation.
A double free was found in the Regexp compiler in Ruby 3.x before 3.0.4 and 3.1.x before 3.1.2. If a victim attempts to create a Regexp from untrusted user input, an attacker may be able to write to unexpected memory locations.
An instance of OpenSSL::X509::Name contains entities such as CN, C and so on. Some two instances of OpenSSL::X509::Name are equal only when all entities are exactly equal. However, there is a bug that the equality check is not correct if the value of an entity of the argument (right-hand side) starts with the value of the receiver (left-hand side). So, if a malicious X.509 certificate is passed to compare with an existing certificate, there is a possibility to be judged incorrectly that they are equal.
External References:
https://www.ruby-lang.org/en/news/2018/10/17/openssl-x509-name-equality-check-does-not-work-correctly-cve-2018-16395/
A buffer overrun vulnerability was discovered in CGI.escapehtml. This can lead to a buffer overflow when a user passes a very large string (> 700 MB) to CGI.escapehtml on a platform where long type takes 4 bytes, typically, Windows.
Last updated 25 August 2025
Last updated 25 August 2025
An exploitable heap overflow vulnerability exists in the Psych::Emitter startdocument function of Ruby. In Psych::Emitter startdocument function heap buffer "head" allocation is made based on tags array length. Specially constructed object passed as element of tags array can increase this array size after mentioned allocation and cause heap overflow.
Dir.open, Dir.new, Dir.entries and Dir.empty? accept the path of the target directory as their parameter. If the parameter contains NUL (\0) bytes, these methods recognize that the path is completed before the NUL bytes. So, if a script accepts an external input as the argument of these methods, the attacker can make the unintentional directory traversal.
Affected versions:
Ruby 2.2 series: 2.2.9 and earlier Ruby 2.3 series: 2.3.6 and earlier Ruby 2.4 series: 2.4.3 and earlier Ruby 2.5 series: 2.5.0 and earlier
External References:
https://www.ruby-lang.org/en/news/2018/03/28/poisoned-nul-byte-dir-cve-2018-8780/
Last updated 25 August 2025
A vulnerability was found in Ruby that allows HTTP header injection. A CGI application using the CGI library may insert untrusted input into the HTTP response header. This issue can allow an attacker to insert a newline character to split a header and inject malicious content to deceive clients.
It was discovered that the Net::FTP module did not properly process filenames in combination with certain operations. A remote attacker could exploit this flaw to execute arbitrary commands by setting up a malicious FTP server and tricking a user or Ruby application into downloading files with specially crafted names using the Net::FTP module.
Last updated 25 August 2025
DL::dlopen could open a library with tainted library name even if $SAFE > 0. This vulnerability affects Ruby versions 1.8, 1.9, 2.1, 2.2.
Upstream patch: https://github.com/ruby/ruby/commit/4600cf725a86ce31266153647ae5aa1197b1215b
Additional information and CVE assignment:
http://seclists.org/oss-sec/2015/q3/222
An issue was discovered in Ruby 4 before 4.0.5. A race condition leading to a use-after-free in the pthread-based getaddrinfo timeout handler (rbgetaddrinfo in ext/socket/raddrinfo.c) allows a remote attacker who can delay DNS responses near the user-specified timeout to crash a Ruby process that calls Addrinfo.getaddrinfo(..., timeout:) or Socket.tcp(..., resolvtimeout:). Memory-corruption-based exploitation is theoretically possible. The attack could, for example, be carried out through a crafted authoritative DNS server or recursive resolver.
An issue was discovered in Ruby before 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3. It does not taint strings that result from unpacking tainted strings with some formats.
Last updated 11 July 2025
Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.splitheadervalue function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted HTTP request that is processed by a backtracking regular expression.
Possible ReDoS vulnerability in Accept header parsing in Action Dispatch
There is a possible ReDoS vulnerability in the Accept header parsing routines of Action Dispatch. This vulnerability has been assigned the CVE identifier CVE-2024-26142.
Versions Affected: >= 7.1.0, < 7.1.3.1 Not affected: < 7.1.0 Fixed Versions: 7.1.3.1
Impact ------ Carefully crafted Accept headers can cause Accept header parsing in Action Dispatch to take an unexpected amount of time, possibly resulting in a DoS vulnerability. All users running an affected release should either upgrade or use one of the workarounds immediately.
Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected.
Releases -------- The fixed releases are available at the normal locations.
Workarounds ----------- There are no feasible workarounds for this issue.
Patches ------- To aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset.
7-1-accept-redox.patch - Patch for 7.1 series
Credits ------- Thanks svalkanov for the report and patch!
A flaw was found in rubygem-json. While parsing certain JSON documents, the json gem (including the one bundled with Ruby) can be coerced into creating arbitrary objects in the target system. This is the same issue as CVE-2013-0269.
In the CGI gem before 0.4.2 for Ruby, a Regular Expression Denial of Service (ReDoS) vulnerability exists in the Util#escapeElement method.
If an attacker sends a large request which contains huge HTTP headers, WEBrick try to process it on memory, so the request causes the out-of-memory DoS attack.
Affected versions:
Ruby 2.2 series: 2.2.9 and earlier Ruby 2.3 series: 2.3.6 and earlier Ruby 2.4 series: 2.4.3 and earlier Ruby 2.5 series: 2.5.0 and earlier
External References:
https://www.ruby-lang.org/en/news/2018/03/28/large-request-dos-in-webrick-cve-2018-8777/
Dir.mktmpdir method introduced by tmpdir library accepts the prefix and the suffix of the directory which is created as the first parameter. The prefix can contain relative directory specifiers "../", so this method can be used to target any directory. So, if a script accepts an external input as the prefix, and the targeted directory has inappropriate permissions or the ruby process has inappropriate privileges, the attacker can create a directory or a file at any directory.
Affected versions:
Ruby 2.2 series: 2.2.9 and earlier Ruby 2.3 series: 2.3.6 and earlier Ruby 2.4 series: 2.4.3 and earlier Ruby 2.5 series: 2.5.0 and earlier
External References:
https://www.ruby-lang.org/en/news/2018/03/28/unintentional-file-and-directory-creation-with-directory-traversal-cve-2018-6914/
In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, an attacker controlling the unpacking format (similar to format string vulnerabilities) can trigger a buffer under-read in the String#unpack method, resulting in a massive and controlled information disclosure.
In Ruby before 2.2.10, 2.3.x before 2.3.7, 2.4.x before 2.4.4, 2.5.x before 2.5.1, and 2.6.0-preview1, the UNIXServer.open and UNIXSocket.open methods are not checked for null characters. It may be connected to an unintended socket.
A flaw was found in ruby, where the date object was found to be vulnerable to a regular expression denial of service (ReDoS) during the parsing of dates. This flaw allows an attacker to hang a ruby application by providing a specially crafted date string. The highest threat to this vulnerability is system availability.
A flaw was found in the way the Ruby REXML library parsed XML documents. Parsing a specially crafted XML document using REXML and writing parsed data back to a new XML document results in creating a document with a different structure. This issue could affect the integrity of processed data in applications using REXML that parse XML documents, write data back to XML, and re-parse them again.
A flaw was found in Ruby. RubyGems cgi gem could allow a remote attacker to conduct spoofing attacks caused by the mishandling of security prefixes in cookie names in the CGI::Cookie.parse function. By sending a specially-crafted request, an attacker could perform cookie prefix spoofing attacks.
Last updated 11 July 2025
An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through 2.7.1. WEBrick, a simple HTTP server bundled with Ruby, had not checked the transfer-encoding header value rigorously. An attacker may potentially exploit this issue to bypass a reverse proxy (which also has a poor header check), which may lead to an HTTP Request Smuggling attack.
In Puma (RubyGem) before 4.3.2 and 3.12.3, if an application using Puma allows untrusted input in a response header, an attacker can use newline characters (i.e. CR, LF or/r, /n) to end the header and inject malicious content, such as additional headers or an entirely new response body. This vulnerability is known as HTTP Response Splitting.
While not an attack in itself, response splitting is a vector for several other attacks, such as cross-site scripting (XSS).
This is related to CVE-2019-16254, which fixed this vulnerability for the WEBrick Ruby web server.
This has been fixed in versions 4.3.2 and 3.12.3 by checking all headers for line endings and rejecting headers with those characters.