# CVE-2025-46727: Unbounded-Parameter DoS in Rack::QueryParser > Attackers can cause denial of service by sending requests with excessive parameters, exhausting memory and CPU in Rack::QueryParser. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 7 May 2025 - **Updated:** 8 May 2025 - **Also known as:** DEBIAN-CVE-2025-46727, GHSA-gjh7-p2fx-99vx, MINI-7rf6-4wjc-h5q8, MINI-m77v-pp9v-prv2, OESA-2025-2211, OESA-2025-2212, OESA-2025-2213, OESA-2025-2214, OESA-2025-2215, OESA-2025-2291, RHSA-2025:7604, RHSA-2025:7605, RHSA-2025:8256, RHSA-2025:8288, RHSA-2025:8289, RHSA-2025:8319, RHSA-2025:8322, RLSA-2025:8256, UBUNTU-CVE-2025-46727, openSUSE-SU-2025:15067-1 ## What is CVE-2025-46727? CVE-2025-46727 is a high-severity denial of service vulnerability in rack, published on 7 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Rack is a modular Ruby web server interface. Prior to versions 2.2.14, 3.0.16, and 3.1.14, `Rack::QueryParser` parses query strings and `application/x-www-form-urlencoded` bodies into Ruby data structures without imposing any limit on the number of parameters, allowing attackers to send requests with extremely large numbers of parameters. The vulnerability arises because `Rack::QueryParser` iterates over each `&`-separated key-value pair and adds it to a Hash without enforcing an upper bound on the total number of parameters. This allows an attacker to send a single request containing hundreds of thousands (or more) of parameters, which consumes excessive memory and CPU during parsing. An attacker can trigger denial of service by sending specifically crafted HTTP requests, which can cause memory exhaustion or pin CPU resources, stalling or crashing the Rack server. This results in full service disruption until the affected worker is restarted. Versions 2.2.14, 3.0.16, and 3.1.14 fix the issue. Some other mitigations are available. One may use middleware to enforce a maximum query string size or parameter count, or employ a reverse proxy (such as Nginx) to limit request sizes and reject oversized query strings or bodies. Limiting request body sizes and query string lengths at the web server or CDN level is an effective mitigation. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption) ## Which versions are affected by CVE-2025-46727? 6 open source packages ship an affected version, including rack. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `rack` | RubyGems | All versions | 2.2.14 | | `rack` | RubyGems | All versions | 2.2.14 | | `rack` | RubyGems | From 3.0 | 3.0.16 | | `rack` | RubyGems | From 3.0 | 3.0.16 | | `rack` | RubyGems | From 3.1 | 3.1.14 | | `rack` | RubyGems | From 3.1 | 3.1.14 | | `cockpit-ha-cluster` | Red Hat:enterprise_linux:10.0 | All versions | 0:0.12.0-3.el10_0.2 | | `pcs` | Red Hat:enterprise_linux:10.0 | All versions | 0:0.12.0-3.el10_0.2 | | `pcs-snmp` | Red Hat:enterprise_linux:10.0 | All versions | 0:0.12.0-3.el10_0.2 | | `pcs` | Red Hat:enterprise_linux:7::server | All versions | 0:0.9.169-3.el7_9.4 | | `pcs-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:0.9.169-3.el7_9.4 | | `pcs-snmp` | Red Hat:enterprise_linux:7::server | All versions | 0:0.9.169-3.el7_9.4 | | `pcs` | Red Hat:enterprise_linux:9::highavailability | All versions | 0:0.11.9-2.el9_6.1 | | `pcs-snmp` | Red Hat:enterprise_linux:9::highavailability | All versions | 0:0.11.9-2.el9_6.1 | | `pcs` | Red Hat:enterprise_linux:9::resilientstorage | All versions | 0:0.11.9-2.el9_6.1 | | `pcs-snmp` | Red Hat:enterprise_linux:9::resilientstorage | All versions | 0:0.11.9-2.el9_6.1 | | `pcs` | Red Hat:rhel_eus:9.2::highavailability | All versions | 0:0.11.4-7.el9_2.5 | | `pcs-snmp` | Red Hat:rhel_eus:9.2::highavailability | All versions | 0:0.11.4-7.el9_2.5 | | `pcs` | Red Hat:rhel_eus:9.2::resilientstorage | All versions | 0:0.11.4-7.el9_2.5 | | `pcs-snmp` | Red Hat:rhel_eus:9.2::resilientstorage | All versions | 0:0.11.4-7.el9_2.5 | | `pcs` | Red Hat:rhel_eus:9.4::highavailability | All versions | 0:0.11.7-2.el9_4.4 | | `pcs-snmp` | Red Hat:rhel_eus:9.4::highavailability | All versions | 0:0.11.7-2.el9_4.4 | | `pcs` | Red Hat:rhel_eus:9.4::resilientstorage | All versions | 0:0.11.7-2.el9_4.4 | | `pcs-snmp` | Red Hat:rhel_eus:9.4::resilientstorage | All versions | 0:0.11.7-2.el9_4.4 | | `rubygem-rack` | Red Hat:satellite:6.16::el8 | All versions | 0:2.2.14-1.el8sat | | `rubygem-rack` | Red Hat:satellite:6.16::el9 | All versions | 0:2.2.14-1.el9sat | | `rubygem-rack` | Red Hat:satellite:6.17::el9 | All versions | 0:2.2.14-1.el9sat | | `rubygem-rack` | Red Hat:satellite_capsule:6.16::el8 | All versions | 0:2.2.14-1.el8sat | | `rubygem-rack` | Red Hat:satellite_capsule:6.16::el9 | All versions | 0:2.2.14-1.el9sat | | `rubygem-rack` | Red Hat:satellite_capsule:6.17::el9 | All versions | 0:2.2.14-1.el9sat | | `pcs` | Rocky Linux:9 | All versions | 0:0.11.9-2.el9_6.1 | | `rubygem-rack-2.2` | openSUSE:Tumbleweed | All versions | 2.2.14-1.1 | Products: Rack Rack. ## How do I fix CVE-2025-46727? Upgrade rack to a fixed version for your release line: 2.2.14, 3.0.16 or 3.1.14. ## Is CVE-2025-46727 being exploited? There is no known exploitation of CVE-2025-46727 in the wild and no public exploit code. ## Other vulnerabilities in rack - [CVE-2026-34785](https://insights.sbomify.com/CVE-2026-34785/): Rack: Local file inclusion in `Rack::Static` via URL Prefix Matching (high 7.5) - [CVE-2026-34827](https://insights.sbomify.com/CVE-2026-34827/): Rack: Algorithmic-Complexity DoS in Rack::Multipart::Parser (high 7.5) - [CVE-2026-34829](https://insights.sbomify.com/CVE-2026-34829/): Rack: Denial of Service via Unbounded Multipart File Upload Without Content-Length (high 7.5) - [CVE-2026-22860](https://insights.sbomify.com/CVE-2026-22860/): Rack has a Directory Traversal via Rack:Directory (high 7.5) - [CVE-2025-61919](https://insights.sbomify.com/CVE-2025-61919/): Rack is vulnerable to a memory-exhaustion DoS through unbounded URL-encoded body parsing (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-46727 and fix it if it is affected. What it is: CVE-2025-46727 is a high-severity denial of service vulnerability in rack, published on 7 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-46727 in the wild and no public exploit code. Affected packages and fixed versions: - rack (RubyGems): affected all versions; fixed in 2.2.14 - rack (RubyGems): affected all versions; fixed in 2.2.14 - rack (RubyGems): affected from 3.0; fixed in 3.0.16 - rack (RubyGems): affected from 3.0; fixed in 3.0.16 - rack (RubyGems): affected from 3.1; fixed in 3.1.14 - rack (RubyGems): affected from 3.1; fixed in 3.1.14 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-46727/ (Markdown: https://insights.sbomify.com/CVE-2025-46727/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-46727 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-46727 - OSV: https://osv.dev/vulnerability/CVE-2025-46727 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-46727/ Summaries are generated and may contain mistakes; the official description above is the record.