CVE-2024-49761

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 only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

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 only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

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 only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

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 only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

A flaw was found in REXML. A remote attacker could exploit inefficient regular expression (regex) parsing when processing hex numeric character references (&#x...;) in XML documents. This could lead to a Regular Expression Denial of Service (ReDoS), impacting the availability of the affected component. This issue is the result of an incomplete fix for CVE-2024-49761.

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 only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

Impact

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 only affected maintained Ruby. Note that Ruby 3.1 will reach EOL on 2025-03.

Patches

The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

Workarounds

Use Ruby 3.2 or later instead of Ruby 3.1.

References

• https://www.ruby-lang.org/en/news/2024/10/28/redos-rexml-cve-2024-49761/: An announce on www.ruby-lang.org

Ruby is a fast and easy interpreted scripting language for object-oriented programming. It has many functions for processing text Files and perform system management tasks (such as Perl).

Security Fix(es):

(CVE-2024-49761)

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The pcs packages provide a command-line configuration system for the Pacemaker and Corosync utilities.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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 only affected maintained Ruby. The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The pcs packages provide a command-line configuration system for the Pacemaker and Corosync utilities.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

• CVE-2024-49761: parse XML with many digits in hex numeric character reference (&#x...) to fix ReDoS vulnerability in REXML

• CVE-2025-46727: unbounded query parsing in bundled rack; a body of repeated keys was parsed in full, exhausting memory. Capped by rack's new query bytesize and parameter-count limits, which pcsd turns into an HTTP 400
• CVE-2025-59830: the same unbounded query parse reached through ';' separated query strings, which rack's parameter counter did not count
• CVE-2025-61770: multipart parsing in bundled rack read the whole request body searching for a boundary that never arrived
• CVE-2025-61771: multipart parsing in bundled rack retained an unbounded non-file field in memory
• CVE-2025-61772: multipart mime part headers in bundled rack were read with no size limit
• CVE-2025-61919: Rack::Request#POST read the entire request body before any limit applied, so a 64 MB body was fully buffered
• CVE-2024-49761: quadratic regular expression in bundled rexml BaseParser#unnormalize; a long run of zeros in a hex character reference made the parser hang
• CVE-2024-52804: quadratic cookie unquoting in bundled tornado _unquote_cookie, which rescanned the value from each escape
• CVE-2025-47287: malformed multipart/form-data in bundled tornado logged a warning per bad part instead of rejecting the request, flooding the log
• CVE-2026-31958: unbounded part count and part header size in bundled tornado multipart parsing
• Stop forwarding client HTTP headers from the Tornado front end to the Ruby part of pcsd, which only ever needed the cookie and the content type

The REXML gem before 3.2.6 has a denial of service vulnerability when it parses an XML that has many <s in an attribute value. (CVE-2024-35176) The REXML gem before 3.3.1 has some DoS vulnerabilities when it parses an XML that has many specific characters such as <, 0 and %>. (CVE-2024-39908) 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 ]>. (CVE-2024-41123) 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. (CVE-2024-41946) The REXML gem before 3.3.6 has a DoS vulnerability when it parses an XML that has many deep elements that have same local name attributes. (CVE-2024-43398) 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...;). (CVE-2024-49761)

rubygem-rexml was updated to 3.3.9:

• fixes CVE-2024-49761, CVE-2024-43398, CVE-2024-41946, CVE-2024-41123, CVE-2024-39908, CVE-2024-35176
• bsc#1232440, bsc#1229673, bsc#1228799, bsc#1228794, bsc#1228072, bsc#1224390

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Ruby is an extensible, interpreted, object-oriented, scripting language. It has features to process text files and to perform system management tasks.

Security Fix(es):

• rexml: REXML ReDoS vulnerability (CVE-2024-49761)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

This update for ruby2.5 fixes the following issues:

• CVE-2024-47220: Fixed a HTTP request smuggling attack in WEBrick (bsc#1230930)
• CVE-2024-49761: Fixed a ReDoS vulnerability in ruby rexml (bsc#1232440)

Other fixes:

• [ruby/uri] Fix quadratic backtracking on invalid relative URI
• [ruby/time] Make RFC2822 regexp linear
• [ruby/time] Fix quadratic backtracking on invalid time
• merge some parts of CGI 0.1.1

This update for ruby2.5 fixes the following issues:

• CVE-2024-35221: Fixed remote DoS via YAML manifest (bsc#1225905)
• CVE-2024-47220: Fixed HTTP request smuggling in WEBrick (bsc#1230930)
• CVE-2024-49761: Fixed ReDOS vulnerability by updating REXML to 3.3.9 (bsc#1232440)
• CVE-2025-24294: Fixed denial of service (DoS) caused by an insufficient check on the length of a decompressed domain name within a DNS packet in resolv gem (bsc#1246430)
• CVE-2025-27219: Fixed denial of service in CGI::Cookie.parse (bsc#1237804)
• CVE-2025-27220: Fixed ReDoS in CGI::Util#escapeElement (bsc#1237806)
• CVE-2025-27221: Fixed userinfo leakage in URI#join, URI#merge and URI#+ (bsc#1237805)
• CVE-2025-6442: Fixed ruby WEBrick read_header HTTP request smuggling vulnerability (bsc#1245254)

This update for ruby2.5 fixes the following issues:

• CVE-2024-49761: ReDoS vulnerability in REXML gem (bsc#1232440 bsc#1232441).
• CVE-2025-58767: denial of service when parsing XML containing multiple XML declarations (bsc#1250016).
• CVE-2026-27820: insufficient checks in zstream_buffer_ungets can lead to a buffer overflow (bsc#1259239).