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Fencer Vulns
high 7.5

CVE-2025-61772 json

Rack's multipart parser buffers unbounded per-part headers, enabling DoS (memory exhaustion)

published 2025-10-07 13 mo ago modified 2026-10-19 20 d ago also EUVD-2025-32055 , GHSA-wpv5-97wm-hp9c

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

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` can accumulate unbounded data when a multipart part’s header block never terminates with the required blank line (`CRLFCRLF`). The parser keeps appending incoming bytes to memory without a size cap, allowing a remote attacker to exhaust memory and cause a denial of service (DoS). Attackers can send incomplete multipart headers to trigger high memory use, leading to process termination (OOM) or severe slowdown. The effect scales with request size limits and concurrency. All applications handling multipart uploads may be affected. Versions 2.2.19, 3.1.17, and 3.2.2 cap per-part header size (e.g., 64 KiB). As a workaround, restrict maximum request sizes at the proxy or web server layer (e.g., Nginx `client_max_body_size`).

Patch / fix

  • rubygems rack 2.2.19, 3.1.17, 3.2.2
  • rack rack 2.2.19, 3.1.17, 3.2.2
  • rack_project rack 2.2.19, 3.1.17, 3.2.2
  • ruby-rack Debian 12 2.2.20-0+deb12u1
  • ruby-rack Debian 13 3.1.18-1~deb13u1
  • ruby-rack Debian 14 3.1.18-1

debian advisories DEBIAN-CVE-2025-61772

  • ruby-rack Ubuntu 22.04 LTS 2.1.4-5ubuntu1.2
  • ruby-rack Ubuntu 24.04 LTS 2.2.7-1ubuntu0.5
  • ruby-rack Ubuntu 25.10 3.1.16-0.1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2025-61772

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • pcs RHEL 10.1 0.12.1-1.el10_1.1
  • pcs-snmp RHEL 10.1 0.12.1-1.el10_1.1
  • cockpit-ha-cluster RHEL 10.1 0.12.1-1.el10_1.1
  • pcs RHEL 9 0.11.10-1.el9_7.1
  • pcs-snmp RHEL 9 0.11.10-1.el9_7.1
  • pcs RHEL 8 0.10.18-2.el8_10.7
  • pcs-snmp RHEL 8 0.10.18-2.el8_10.7
  • pcs RHEL 9 0.11.9-2.el9_6.2

red hat advisories RHSA-2025:21036RHSA-2025:20962RHSA-2025:19948RHSA-2025:19800RHSA-2025:19736RHSA-2025:19734

  • rubygem-rack-2.2 openSUSE Tumbleweed 2.2.22-1.1
  • rubygem-rack-2.2 openSUSE Tumbleweed 2.2.19-1.1

opensuse advisories openSUSE-SU-2026:10286-1openSUSE-SU-2025:15621-1

  • pcs AlmaLinux 9 0.11.10-1.el9_7.1
  • pcs-snmp AlmaLinux 9 0.11.10-1.el9_7.1
  • cockpit-ha-cluster AlmaLinux 10 0.12.1-1.el10_1.1
  • pcs AlmaLinux 8 0.10.18-2.el8_10.7.alma.1
  • pcs-snmp AlmaLinux 8 0.10.18-2.el8_10.7.alma.1

almalinux advisories ALSA-2025:20962ALSA-2025:21036ALSA-2025:19719

  • pcs Rocky Linux 9 0.11.10-1.el9_7.1
  • pcs Rocky Linux 9 0.11.9-2.el9_6.2
  • pcs Rocky Linux 8 0.10.18-2.el8_10.7

rocky linux advisories RLSA-2025:20962RLSA-2025:19512RLSA-2025:19719

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-61772 updated cvss 5.3

rack: Rack memory exhaustion denial of service

  • Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/vector-rhel9, openshift-logging/fluentd-rhel8, openshift-logging/fluentd-rhel9, openshift-logging/eventrouter-rhel9, openshift-logging/logging-view-plugin-rhel9, openshift-logging/cluster-logging-rhel9-operator, +2 more Red Hat 3scale API Management Platform 2 3scale-amp21/zync, 3scale-amp22/zync, 3scale-amp24/zync, 3scale-amp25/zync, 3scale-amp26/zync, 3scale-amp2/zync-rhel7, +2 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 7 pcs, pcs-snmp, python-clufter
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 ubi8/ruby-25, ubi8/ruby-33, rhel8/ruby-25, rhel8/ruby-33 Red Hat Enterprise Linux 9 ubi9/ruby-30, ubi9/ruby-31, ubi9/ruby-33, rhel9/ruby-30, rhel9/ruby-31, rhel9/ruby-33 Red Hat Enterprise Linux 10 ubi10/ruby-33, rhel10/ruby-33 Red Hat OpenStack Platform 13 (Queens) rhosp13/openstack-redis, rhosp13/openstack-haproxy, rhosp13/openstack-mariadb, rhosp13/openstack-rabbitmq, rhosp13/openstack-ovn-northd, rhosp13/openstack-manila-share, +2 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux High Availability (v. 9) pcs 0.11.9-2.el9_6.2, pcs 0.11.10-1.el9_7.1, pcs-snmp 0.11.9-2.el9_6.2, pcs-snmp 0.11.10-1.el9_7.1
    fixed: vendor fix RHSA-2025:19512
  • Red Hat Enterprise Linux High Availability (v. 10) pcs 0.12.0-3.el10_0.3, pcs 0.12.1-1.el10_1.1, pcs-snmp 0.12.0-3.el10_0.3, pcs-snmp 0.12.1-1.el10_1.1, cockpit-ha-cluster 0.12.0-3.el10_0.3, cockpit-ha-cluster 0.12.1-1.el10_1.1
    fixed: vendor fix RHSA-2025:19513
  • Red Hat Enterprise Linux High Availability AUS (v.8.4) pcs 0.10.8-1.el8_4.8, pcs-snmp 0.10.8-1.el8_4.8
    fixed: vendor fix RHSA-2025:19948
  • Red Hat Enterprise Linux High Availability E4S (v.8.6) pcs 0.10.12-6.el8_6.10, pcs-snmp 0.10.12-6.el8_6.10
    fixed: vendor fix RHSA-2025:19734
  • Red Hat Enterprise Linux High Availability E4S (v.8.8) pcs 0.10.15-4.el8_8.9, pcs-snmp 0.10.15-4.el8_8.9
    fixed: vendor fix RHSA-2025:19647
show 13 more
  • Red Hat Enterprise Linux High Availability E4S (v.9.0) pcs 0.11.1-10.el9_0.9, pcs-snmp 0.11.1-10.el9_0.9
    fixed: vendor fix RHSA-2025:19800
  • Red Hat Enterprise Linux High Availability E4S (v.9.2) pcs 0.11.4-7.el9_2.6, pcs-snmp 0.11.4-7.el9_2.6
    fixed: vendor fix RHSA-2025:19733
  • Red Hat Enterprise Linux High Availability EUS (v.9.4) pcs 0.11.7-2.el9_4.5, pcs-snmp 0.11.7-2.el9_4.5
    fixed: vendor fix RHSA-2025:19736
  • Red Hat Enterprise Linux High Availability TUS (v.8.6) pcs 0.10.12-6.el8_6.10, pcs-snmp 0.10.12-6.el8_6.10
    fixed: vendor fix RHSA-2025:19734
  • Red Hat Enterprise Linux High Availability TUS (v.8.8) pcs 0.10.15-4.el8_8.9, pcs-snmp 0.10.15-4.el8_8.9
    fixed: vendor fix RHSA-2025:19647
  • Red Hat Enterprise Linux HighAvailability (v. 8) pcs 0.10.18-2.el8_10.7, pcs-snmp 0.10.18-2.el8_10.7
    fixed: vendor fix RHSA-2025:19719
  • Red Hat Enterprise Linux HighAvailability EUS EXTENSION (v.8.4) pcs 0.10.8-1.el8_4.8, pcs-snmp 0.10.8-1.el8_4.8
    fixed: vendor fix RHSA-2025:19948
  • Red Hat Enterprise Linux Resilient Storage (v. 9) pcs 0.11.9-2.el9_6.2, pcs 0.11.10-1.el9_7.1, pcs-snmp 0.11.9-2.el9_6.2, pcs-snmp 0.11.10-1.el9_7.1
    fixed: vendor fix RHSA-2025:19512
  • Red Hat Enterprise Linux Resilient Storage E4S (v.9.2) pcs 0.11.4-7.el9_2.6, pcs-snmp 0.11.4-7.el9_2.6
    fixed: vendor fix RHSA-2025:19733
  • Red Hat Enterprise Linux Resilient Storage EUS (v.9.4) pcs 0.11.7-2.el9_4.5, pcs-snmp 0.11.7-2.el9_4.5
    fixed: vendor fix RHSA-2025:19736
  • Red Hat Enterprise Linux ResilientStorage (v. 8) pcs 0.10.18-2.el8_10.7, pcs-snmp 0.10.18-2.el8_10.7
    fixed: vendor fix RHSA-2025:19719
  • Red Hat Enterprise Linux ResilientStorage E4S (v.9.0) pcs 0.11.1-10.el9_0.9, pcs-snmp 0.11.1-10.el9_0.9
    fixed: vendor fix RHSA-2025:19800
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.93% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
rubygems rack
<2.2.19
>=3.1, <3.1.17
>=3.2, <3.2.2
2.2.19
3.1.17
3.2.2

Affected products

  • rack rack

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.