CVE-2025-61919

Summary

Rack::Request#POST reads the entire request body into memory for Content-Type: application/x-www-form-urlencoded, calling rack.input.read(nil) without enforcing a length or cap. Large request bodies can therefore be buffered completely into process memory before parsing, leading to denial of service (DoS) through memory exhaustion.

Details

When handling non-multipart form submissions, Rack’s request parser performs:

form_vars = get_header(RACK_INPUT).read

Since read is called with no argument, the entire request body is loaded into a Ruby String. This occurs before query parameter parsing or enforcement of any params_limit. As a result, Rack applications without an upstream body-size limit can experience unbounded memory allocation proportional to request size.

Impact

Attackers can send large application/x-www-form-urlencoded bodies to consume process memory, causing slowdowns or termination by the operating system (OOM). The effect scales linearly with request size and concurrency. Even with parsing limits configured, the issue occurs before those limits are enforced.

Mitigation

• Update to a patched version of Rack that enforces form parameter limits using query_parser.bytesize_limit, preventing unbounded reads of application/x-www-form-urlencoded bodies.
• Enforce strict maximum body size at the proxy or web server layer (e.g., Nginx client_max_body_size, Apache LimitRequestBody).

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

Security Fix(es):

• rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters (CVE-2025-59830)

• rack: Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion) (CVE-2025-61770)

• rack: Rack's multipart parser buffers large non?file fields entirely in memory, enabling DoS (memory exhaustion) (CVE-2025-61771)

• rack: Rack memory exhaustion denial of service (CVE-2025-61772)

• rubygem-rack: Unbounded read in Rack::Request form parsing can lead to memory exhaustion (CVE-2025-61919)

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):

• rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters (CVE-2025-59830)

• rack: Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion) (CVE-2025-61770)

• rack: Rack's multipart parser buffers large non?file fields entirely in memory, enabling DoS (memory exhaustion) (CVE-2025-61771)

• rack: Rack memory exhaustion denial of service (CVE-2025-61772)

• rubygem-rack: Unbounded read in Rack::Request form parsing can lead to memory exhaustion (CVE-2025-61919)

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):

• rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters (CVE-2025-59830)

• rack: Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion) (CVE-2025-61770)

• rack: Rack's multipart parser buffers large non?file fields entirely in memory, enabling DoS (memory exhaustion) (CVE-2025-61771)

• rack: Rack memory exhaustion denial of service (CVE-2025-61772)

• rubygem-rack: Unbounded read in Rack::Request form parsing can lead to memory exhaustion (CVE-2025-61919)

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.

Rack is a modular Ruby web server interface. Prior to versions 2.2.20, 3.1.18, and 3.2.3, Rack::Request#POST reads the entire request body into memory for Content-Type: application/x-www-form-urlencoded, calling rack.input.read(nil) without enforcing a length or cap. Large request bodies can therefore be buffered completely into process memory before parsing, leading to denial of service (DoS) through memory exhaustion. Users should upgrade to Rack version 2.2.20, 3.1.18, or 3.2.3, anu of which enforces form parameter limits using query_parser.bytesize_limit, preventing unbounded reads of application/x-www-form-urlencoded bodies. Additionally, enforce strict maximum body size at the proxy or web server layer (e.g., Nginx client_max_body_size, Apache LimitRequestBody).

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

Security Fix(es):

• rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters (CVE-2025-59830)
• rack: Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion) (CVE-2025-61770)
• rack: Rack's multipart parser buffers large non?file fields entirely in memory, enabling DoS (memory exhaustion) (CVE-2025-61771)
• rack: Rack memory exhaustion denial of service (CVE-2025-61772)
• rubygem-rack: Unbounded read in Rack::Request form parsing can lead to memory exhaustion (CVE-2025-61919)

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):

• rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters (CVE-2025-59830)
• rack: Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion) (CVE-2025-61770)
• rack: Rack's multipart parser buffers large non?file fields entirely in memory, enabling DoS (memory exhaustion) (CVE-2025-61771)
• rack: Rack memory exhaustion denial of service (CVE-2025-61772)
• rubygem-rack: Unbounded read in Rack::Request form parsing can lead to memory exhaustion (CVE-2025-61919)

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):

• rubygem-rack: Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters (CVE-2025-59830)
• rack: Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion) (CVE-2025-61770)
• rack: Rack's multipart parser buffers large non?file fields entirely in memory, enabling DoS (memory exhaustion) (CVE-2025-61771)
• rack: Rack memory exhaustion denial of service (CVE-2025-61772)
• rubygem-rack: Unbounded read in Rack::Request form parsing can lead to memory exhaustion (CVE-2025-61919)

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-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

• Update bundled rubygem rack to 2.2.20
• CVE-2024-25126: fix ReDoS in Rack::MediaType content type parsing
• CVE-2024-26141: fix response amplification from crafted Range headers
• CVE-2024-26146: fix ReDoS in Accept and Forwarded header parsing
• CVE-2025-46727: fix unbounded parameter count in Rack::QueryParser
• CVE-2025-59830: fix params_limit bypass via semicolon-separated parameters
• CVE-2025-61770: fix unbounded multipart preamble buffering
• CVE-2025-61771: fix unbounded buffering of non-file multipart fields
• CVE-2025-61772: fix unbounded multipart part header buffering
• CVE-2025-61919: fix unbounded form body read in Rack::Request#POST
• Handle Rack::QueryParser::QueryLimitError in pcsd, returning 400 instead of 500
• CVE-2026-31958: cap multipart part count and part header size in bundled tornado
• Disable multipart request parsing in pcsd, which does not use it
• Drop i686 from ExclusiveArch: the bundled web UI needs npm at build time and npm has no i686 build, so the i686 buildroot cannot be created

• Update bundled rubygem rack to 2.2.20
• CVE-2024-25126: fix ReDoS in Rack::MediaType content type parsing
• CVE-2024-26141: fix response amplification from crafted Range headers
• CVE-2024-26146: fix ReDoS in Accept and Forwarded header parsing
• CVE-2025-46727: fix unbounded parameter count in Rack::QueryParser
• CVE-2025-59830: fix params_limit bypass via semicolon-separated parameters
• CVE-2025-61770: fix unbounded multipart preamble buffering
• CVE-2025-61771: fix unbounded buffering of non-file multipart fields
• CVE-2025-61772: fix unbounded multipart part header buffering
• CVE-2025-61919: fix unbounded form body read in Rack::Request#POST
• Handle Rack::QueryParser::QueryLimitError in pcsd, returning 400 instead of 500
• CVE-2026-31958: cap multipart part count and part header size in bundled tornado
• Disable multipart request parsing in pcsd, which does not use it
• Drop i686 from ExclusiveArch: the bundled web UI needs npm at build time and npm has no i686 build, so the i686 buildroot cannot be created

• fix CVE-2025-61919: update bundled rubygem rack from 2.2.6.4 to 2.2.20, bounding the Rack::Request#POST form body read

• Fix CVE-2025-46727: limit number and bytesize of query parameters in bundled rubygem rack
• Fix CVE-2025-61919: bound the read of urlencoded request bodies in bundled rubygem rack
• Fix CVE-2025-61771: limit multipart data retained in memory in bundled rubygem rack
• Fix CVE-2025-61772: limit the multipart part header size in bundled rubygem rack
• Skip the pcs tests that need pacemaker >= 1.1.23 when the build root has an older one (CloudLinux 7)

Unbounded-Parameter DoS in Rack::QueryParser. (CVE-2025-46727) ReDoS Vulnerability in Rack::Multipart handle_mime_head. (CVE-2025-49007) Rack QueryParser has an unsafe default allowing params_limit bypass via semicolon-separated parameters. (CVE-2025-59830) Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion). (CVE-2025-61770) Rack's multipart parser buffers large non‑file fields entirely in memory, enabling DoS (memory exhaustion). (CVE-2025-61771) Rack's multipart parser buffers unbounded per-part headers, enabling DoS (memory exhaustion). (CVE-2025-61772) Rack is vulnerable to a memory-exhaustion DoS through unbounded URL-encoded body parsing. (CVE-2025-61919) Rack has Possible Information Disclosure Vulnerability. (CVE-2025-61780)

These are all security issues fixed in the ruby3.4-rubygem-rack-2.2-2.2.20-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the ruby4.0-rubygem-rack-2.2-2.2.22-1.1 package on the GA media of openSUSE Tumbleweed.

This update for hawk2 fixes the following issues:

• Bump ruby gem rack to 3.1.18 (bsc#1251939).
• Bump ruby gem uri to 1.0.4.
• Fix the mtime in manifest.json (bsc#1230275).
• Make builds determinitstic (bsc#1230275).
• Bump rails version from 8.0.2 to 8.0.2.1 (bsc#1248100).
• Require openssl explicitly (bsc#1247899).

This update for rubygem-rack fixes the following issues:

• Update to version 2.2.20 (bsc#1251936)
• CVE-2025-61919: Fixed application/x-www-form-urlencoded, calling rack.input.read(nil)` without enforcing a length or cap (bsc#1251936)
• CVE-2025-61780: Fixed improper handling of headers in Rack::Sendfile allows for bypass of proxy-level access restrictions (bsc#1253951)

This update for hawk2 fixes the following issues:

• Bump ruby gem rack to 3.1.18 (bsc#1251939).
• Bump ruby gem uri to 1.0.4.
• Fix the mtime in manifest.json (bsc#1230275).
• Make builds determinitstic (bsc#1230275).
• Bump rails version from 8.0.2 to 8.0.2.1 (bsc#1248100).
• Require openssl explicitly (bsc#1247899).

This update for hawk2 fixes the following issues:

• Bump ruby gem rack to 3.1.18 (bsc#1251939).
• Bump ruby gem uri to 1.0.4.
• Fix the mtime in manifest.json (bsc#1230275).
• Make builds determinitstic (bsc#1230275).
• Bump rails version from 8.0.2 to 8.0.2.1 (bsc#1248100).
• Require openssl explicitly (bsc#1247899).