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Full vulnerability report · 2025
CVE-2025-61771High confidence

Rack's multipart parser buffers large non‑file fields entirely in memory, enabling DoS (memory exhaustion)

rack · rack

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archiveruby-rackVendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.2.2.7-1ubuntu0.5Canonical record ↗Source updated 11 Sept 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2025-61771 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityrack: Rack's multipart parser buffers large non‑file fields entirely in memory, enabling DoS (memory exhaustion)
16 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • 3scale-amp2/zync-rhel7 as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp2/zync-rhel8 as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp2/zync-rhel9 as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp21/zync as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp22/zync as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp24/zync as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp25/zync as a component of Red Hat 3scale API Management Platform 2
  • 3scale-amp26/zync as a component of Red Hat 3scale API Management Platform 2
  • rhosp13/openstack-cinder-api as a component of Red Hat OpenStack Platform 13 (Queens)
  • rhosp13/openstack-cinder-backup as a component of Red Hat OpenStack Platform 13 (Queens)
  • rhosp13/openstack-cinder-scheduler as a component of Red Hat OpenStack Platform 13 (Queens)
  • rhosp13/openstack-cinder-volume as a component of Red Hat OpenStack Platform 13 (Queens)
Summary
A flaw was found in Rack where Rack::Multipart::Parser stores non-file form fields entirely in memory without size limits. An attacker can send a multipart/form-data request with an extremely large text field, causing the server to allocate large amounts of memory which leads to a denial of service crash due to out-of-memory issue.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-32056

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, ``Rack::Multipart::Parser` stores non-file form fields (parts without a `filename`) entirely in memory as Ruby `String` objects. A single large text field in a multipart/form-data request (hundreds of megabytes or more) can consume equivalent process memory, potentially leading to out-of-memory (OOM) conditions and denial of service (DoS). Attackers can send large non-file fields to trigger excessive memory usage. Impact scales with request size and concurrency, potentially leading to worker crashes or severe garbage-collection overhead. All Rack applications processing multipart form submissions are affected. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a reasonable size cap for non-file fields (e.g., 2 MiB). Workarounds include restricting maximum request body size at the web-server or proxy layer (e.g., Nginx `client_max_body_size`) and validating and rejecting unusually large form fields at the application level.

What

Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, ``Rack::Multipart::Parser` stores non-file form fields (parts without a `filename`) entirely in memory as Ruby `String` objects. A single large text field in a multipart/form-data request (hundreds of megabytes or more) can consume equivalent process memory, potentially leading to out-of-memory (OOM) conditions and denial of service (DoS). Attackers can send large non-file fields to trigger excessive memory usage. Impact scales with request size and concurrency, potentially leading to worker crashes or severe garbage-collection overhead. All Rack applications processing multipart form submissions are affected. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a reasonable size cap for non-file fields (e.g., 2 MiB). Workarounds include restricting maximum request body size at the web-server or proxy layer (e.g., Nginx `client_max_body_size`) and validating and rejecting unusually large form fields at the application level.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, ``Rack::Multipart::Parser` stores non-file form fields (parts without a `filename`) entirely in memory as Ruby `String` objects. A single large text field in a multipart/form-data request (hundreds of megabytes or more) can consume equivalent process memory, potentially leading to out-of-memory (OOM) conditions and denial of service (DoS). Attackers can send large non-file fields to trigger excessive memory usage. Impact scales with request size and concurrency, potentially leading to worker crashes or severe garbage-collection overhead. All Rack applications processing multipart form submissions are affected. Versions 2.2.19, 3.1.17, and 3.2.2 enforce a reasonable size cap for non-file fields (e.g., 2 MiB). Workarounds include restricting maximum request body size at the web-server or proxy layer (e.g., Nginx `client_max_body_size`) and validating and rejecting unusually large form fields at the application level.

Why

The product does not properly control the allocation and maintenance of a limited resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Uncontrolled Resource Consumption → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-400 ↗

CWE-400: Uncontrolled Resource Consumption. The product does not properly control the allocation and maintenance of a limited resource.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedDenial of serviceCWE-400
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2025-2482Red Hat Enterprise Linux: Mehrere Schwachstellen ermöglichen Denial of Service

Ein Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0326Multiples vulnérabilités dans les produits VMware

d?id=CVE-2025-61725 Référence CVE CVE-2025-61726 https://www.cve.org/CVERecord?id=CVE-2025-61726 Référence CVE CVE-2025-61727 https://www.cve.org/CVERecord?id=CVE-2025-61727 Référence CVE CVE-2025-61728 https://www.cve.org/CVERecord?id=CVE-2025-61728 Référence CVE CVE-2025-61729 https://www.cve.org/CVERecord?id=CVE-2025-61729 Référence CVE CVE-2025-61730 https://www.cve.org/CVERecord?id=CVE-2025-61730 Référence CVE CVE-2025-61731 https://www.cve.org/CVERecord?id=CVE-2025-61731 Référence CVE CVE-2025-61732 https://www.cve.org/CVERecord?id=CVE-2025-61732 Référence CVE CVE-2025-61770 https://www.cve.org/CVERecord?id=CVE-2025-61770 Référence CVE CVE-2025-61771 https://www.cve.org/CVERecord?id=CVE-2025-61771 Référence CVE CVE-2025-61772 https://www.cve.org/CVERecord?id=CVE-2025-61772 Référence CVE CVE-2025-61780 https://www.cve.org/CVERecord?id=CVE-2025-61780 Référence CVE CVE-2025-61795 https://www.cve.org/CVERecord?id=CVE-2025-61795 Référence CVE CVE-2025-61919 https://www.cve.org/CVERecord?id=CVE-2025-61919 Référence CVE CVE-2025-61984 https://www.cve.org/CVERecord?id=CVE-2025-61984 Référence CVE CVE-2025-61985 https://www.cve.org/CVERecord?id=CVE-2025-61985 Référence CVE CVE-2025-62525 https://www.cve.org/CVERecord?id=CVE-2025-62525 Référence CVE CVE-2025-62526 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-1129Multiples vulnérabilités dans les produits VMware

d?id=CVE-2025-59419 Référence CVE CVE-2025-59830 https://www.cve.org/CVERecord?id=CVE-2025-59830 Référence CVE CVE-2025-61723 https://www.cve.org/CVERecord?id=CVE-2025-61723 Référence CVE CVE-2025-61724 https://www.cve.org/CVERecord?id=CVE-2025-61724 Référence CVE CVE-2025-61725 https://www.cve.org/CVERecord?id=CVE-2025-61725 Référence CVE CVE-2025-61727 https://www.cve.org/CVERecord?id=CVE-2025-61727 Référence CVE CVE-2025-61729 https://www.cve.org/CVERecord?id=CVE-2025-61729 Référence CVE CVE-2025-61748 https://www.cve.org/CVERecord?id=CVE-2025-61748 Référence CVE CVE-2025-61770 https://www.cve.org/CVERecord?id=CVE-2025-61770 Référence CVE CVE-2025-61771 https://www.cve.org/CVERecord?id=CVE-2025-61771 Référence CVE CVE-2025-61772 https://www.cve.org/CVERecord?id=CVE-2025-61772 Référence CVE CVE-2025-61780 https://www.cve.org/CVERecord?id=CVE-2025-61780 Référence CVE CVE-2025-61795 https://www.cve.org/CVERecord?id=CVE-2025-61795 Référence CVE CVE-2025-61919 https://www.cve.org/CVERecord?id=CVE-2025-61919 Référence CVE CVE-2025-64329 https://www.cve.org/CVERecord?id=CVE-2025-64329 Référence CVE CVE-2025-64756 https://www.cve.org/CVERecord?id=CVE-2025-64756 Référence CVE CVE-2025-66030 https://www.cve.org/CVERecord?id=CVE-2025-66030 Référence CVE CVE-2025-66031 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0969Multiples vulnérabilités dans les produits VMware

.org/CVERecord?id=CVE-2025-6020 Référence CVE CVE-2025-6021 https://www.cve.org/CVERecord?id=CVE-2025-6021 Référence CVE CVE-2025-6051 https://www.cve.org/CVERecord?id=CVE-2025-6051 Référence CVE CVE-2025-6052 https://www.cve.org/CVERecord?id=CVE-2025-6052 Référence CVE CVE-2025-6069 https://www.cve.org/CVERecord?id=CVE-2025-6069 Référence CVE CVE-2025-6141 https://www.cve.org/CVERecord?id=CVE-2025-6141 Référence CVE CVE-2025-6170 https://www.cve.org/CVERecord?id=CVE-2025-6170 Référence CVE CVE-2025-61748 https://www.cve.org/CVERecord?id=CVE-2025-61748 Référence CVE CVE-2025-61770 https://www.cve.org/CVERecord?id=CVE-2025-61770 Référence CVE CVE-2025-61771 https://www.cve.org/CVERecord?id=CVE-2025-61771 Référence CVE CVE-2025-61772 https://www.cve.org/CVERecord?id=CVE-2025-61772 Référence CVE CVE-2025-61780 https://www.cve.org/CVERecord?id=CVE-2025-61780 Référence CVE CVE-2025-61795 https://www.cve.org/CVERecord?id=CVE-2025-61795 Référence CVE CVE-2025-61919 https://www.cve.org/CVERecord?id=CVE-2025-61919 Référence CVE CVE-2025-61921 https://www.cve.org/CVERecord?id=CVE-2025-61921 Référence CVE CVE-2025-61984 https://www.cve.org/CVERecord?id=CVE-2025-61984 Référence CVE CVE-2025-61985 https://www.cve.org/CVERecord?id=CVE-2025-61985 Référence CVE CVE-2025-62171 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0967Multiples vulnérabilités dans les produits VMware

ord?id=CVE-2025-58446 Référence CVE CVE-2025-58754 https://www.cve.org/CVERecord?id=CVE-2025-58754 Référence CVE CVE-2025-58767 https://www.cve.org/CVERecord?id=CVE-2025-58767 Référence CVE CVE-2025-59425 https://www.cve.org/CVERecord?id=CVE-2025-59425 Référence CVE CVE-2025-59830 https://www.cve.org/CVERecord?id=CVE-2025-59830 Référence CVE CVE-2025-6069 https://www.cve.org/CVERecord?id=CVE-2025-6069 Référence CVE CVE-2025-61620 https://www.cve.org/CVERecord?id=CVE-2025-61620 Référence CVE CVE-2025-61748 https://www.cve.org/CVERecord?id=CVE-2025-61748 Référence CVE CVE-2025-61770 https://www.cve.org/CVERecord?id=CVE-2025-61770 Référence CVE CVE-2025-61771 https://www.cve.org/CVERecord?id=CVE-2025-61771 Référence CVE CVE-2025-61772 https://www.cve.org/CVERecord?id=CVE-2025-61772 Référence CVE CVE-2025-61780 https://www.cve.org/CVERecord?id=CVE-2025-61780 Référence CVE CVE-2025-61795 https://www.cve.org/CVERecord?id=CVE-2025-61795 Référence CVE CVE-2025-61919 https://www.cve.org/CVERecord?id=CVE-2025-61919 Référence CVE CVE-2025-61921 https://www.cve.org/CVERecord?id=CVE-2025-61921 Référence CVE CVE-2025-6242 https://www.cve.org/CVERecord?id=CVE-2025-6242 Référence CVE CVE-2025-8194 https://www.cve.org/CVERecord?id=CVE-2025-8194 Référence CVE CVE-2025-8291 https://www.cve.org/CVERecord?id=CVE-2

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 7 Oct 2025 · Last source change 7 Oct 2025, 17:52 UTC · CWE-400 · Uncontrolled Resource Consumption

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-32056
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2025-32056↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Patch or update reference↗Patch or update reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-61771 · cve.blacktree.nl