Staging Environment: Content and features may be unstable or change without notice.
Search for vulnerabilities
Vulnerability details: VCID-47ja-djzb-2bbw
Vulnerability ID VCID-47ja-djzb-2bbw
Aliases CVE-2025-46727
GHSA-gjh7-p2fx-99vx
Summary Rack has an Unbounded-Parameter DoS in Rack::QueryParser ## Summary `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. ## Details 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. ## Impact 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. ## Mitigation - Update to a version of Rack that limits the number of parameters parsed, or - 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.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (4)
System Score Found at
cvssv3 7.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2025-46727.json
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
epss 0.00808 https://api.first.org/data/v1/epss?cve=CVE-2025-46727
cvssv3.1 7.5 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-gjh7-p2fx-99vx
cvssv3.1 7.5 https://github.com/rack/rack
generic_textual HIGH https://github.com/rack/rack
cvssv3.1 7.5 https://github.com/rack/rack/commit/2bb5263b464b65ba4b648996a579dbd180d2b712
generic_textual HIGH https://github.com/rack/rack/commit/2bb5263b464b65ba4b648996a579dbd180d2b712
ssvc Track https://github.com/rack/rack/commit/2bb5263b464b65ba4b648996a579dbd180d2b712
cvssv3.1 7.5 https://github.com/rack/rack/commit/3f5a4249118d09d199fe480466c8c6717e43b6e3
generic_textual HIGH https://github.com/rack/rack/commit/3f5a4249118d09d199fe480466c8c6717e43b6e3
ssvc Track https://github.com/rack/rack/commit/3f5a4249118d09d199fe480466c8c6717e43b6e3
cvssv3.1 7.5 https://github.com/rack/rack/commit/cd6b70a1f2a1016b73dc906f924869f4902c2d74
generic_textual HIGH https://github.com/rack/rack/commit/cd6b70a1f2a1016b73dc906f924869f4902c2d74
ssvc Track https://github.com/rack/rack/commit/cd6b70a1f2a1016b73dc906f924869f4902c2d74
cvssv3 7.5 https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
cvssv3.1 7.5 https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
cvssv3.1_qr HIGH https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
generic_textual HIGH https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
ssvc Track https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
cvssv3.1 7.5 https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2025-46727.yml
generic_textual HIGH https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2025-46727.yml
cvssv3.1 7.5 https://nvd.nist.gov/vuln/detail/CVE-2025-46727
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2025-46727
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2025-46727.json
https://api.first.org/data/v1/epss?cve=CVE-2025-46727
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-46727
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://github.com/rack/rack
https://github.com/rack/rack/commit/2bb5263b464b65ba4b648996a579dbd180d2b712
https://github.com/rack/rack/commit/3f5a4249118d09d199fe480466c8c6717e43b6e3
https://github.com/rack/rack/commit/cd6b70a1f2a1016b73dc906f924869f4902c2d74
https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2025-46727.yml
https://nvd.nist.gov/vuln/detail/CVE-2025-46727
1104927 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1104927
2364966 https://bugzilla.redhat.com/show_bug.cgi?id=2364966
GHSA-gjh7-p2fx-99vx https://github.com/advisories/GHSA-gjh7-p2fx-99vx
RHSA-2025:7604 https://access.redhat.com/errata/RHSA-2025:7604
RHSA-2025:7605 https://access.redhat.com/errata/RHSA-2025:7605
RHSA-2025:8254 https://access.redhat.com/errata/RHSA-2025:8254
RHSA-2025:8256 https://access.redhat.com/errata/RHSA-2025:8256
RHSA-2025:8279 https://access.redhat.com/errata/RHSA-2025:8279
RHSA-2025:8288 https://access.redhat.com/errata/RHSA-2025:8288
RHSA-2025:8289 https://access.redhat.com/errata/RHSA-2025:8289
RHSA-2025:8290 https://access.redhat.com/errata/RHSA-2025:8290
RHSA-2025:8291 https://access.redhat.com/errata/RHSA-2025:8291
RHSA-2025:8319 https://access.redhat.com/errata/RHSA-2025:8319
RHSA-2025:8322 https://access.redhat.com/errata/RHSA-2025:8322
RHSA-2025:8323 https://access.redhat.com/errata/RHSA-2025:8323
RHSA-2025:9838 https://access.redhat.com/errata/RHSA-2025:9838
USN-7507-1 https://usn.ubuntu.com/7507-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2025-46727.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/rack/rack
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/rack/rack/commit/2bb5263b464b65ba4b648996a579dbd180d2b712
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none


Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2025-05-08T14:00:33Z/ Found at https://github.com/rack/rack/commit/2bb5263b464b65ba4b648996a579dbd180d2b712
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/rack/rack/commit/3f5a4249118d09d199fe480466c8c6717e43b6e3
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none


Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2025-05-08T14:00:33Z/ Found at https://github.com/rack/rack/commit/3f5a4249118d09d199fe480466c8c6717e43b6e3
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/rack/rack/commit/cd6b70a1f2a1016b73dc906f924869f4902c2d74
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none


Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2025-05-08T14:00:33Z/ Found at https://github.com/rack/rack/commit/cd6b70a1f2a1016b73dc906f924869f4902c2d74
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none


Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2025-05-08T14:00:33Z/ Found at https://github.com/rack/rack/security/advisories/GHSA-gjh7-p2fx-99vx
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2025-46727.yml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2025-46727
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Exploit Prediction Scoring System (EPSS)
Percentile 0.74158
EPSS Score 0.00808
Published At April 2, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:57:04.516281+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/05/GHSA-gjh7-p2fx-99vx/GHSA-gjh7-p2fx-99vx.json 38.0.0