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Fencer Vulns
medium 5.9

CVE-2026-2581 json

undici is vulnerable to Unbounded Memory Consumption in in Undici's DeduplicationHandler via Response Buffering leads to DoS

published 2026-03-12 7 mo ago modified 2026-09-10 1 mo ago also GHSA-phc3-fgpg-7m6h , EUVD-2026-11705

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

This is an uncontrolled resource consumption vulnerability (CWE-400) that can lead to Denial of Service (DoS).

In vulnerable Undici versions, when interceptors.deduplicate() is enabled, response data for deduplicated requests could be accumulated in memory for downstream handlers. An attacker-controlled or untrusted upstream endpoint can exploit this with large/chunked responses and concurrent identical requests, causing high memory usage and potential OOM process termination.

Impacted users are applications that use Undici’s deduplication interceptor against endpoints that may produce large or long-lived response bodies.

PatchesThe issue has been patched by changing deduplication behavior to stream response chunks to downstream handlers as they arrive (instead of full-body accumulation), and by preventing late deduplication when body streaming has already started.

Users should upgrade to the first official Undici (and Node.js, where applicable) releases that include this patch.

Patch / fix

  • npm undici 7.24.0
  • undici undici 6.24.0: 7.24.0
  • node-undici Debian 14 7.24.5+dfsg+~cs3.2.0-1

debian advisories DEBIAN-CVE-2026-2581

  • nodejs24 RHEL 10.1 1:24.14.1-2.el10_1
  • nodejs24-npm RHEL 10.1 1:11.11.0-1.24.14.1.2.el10_1
  • nodejs24-libs RHEL 10.1 1:24.14.1-2.el10_1
  • nodejs24-full-i18n RHEL 10.1 1:24.14.1-2.el10_1
  • npm RHEL 8 1:11.11.0-1.24.14.1.2.module+el8.10.0+24190+49a46c75
  • nodejs RHEL 8 1:24.14.1-2.module+el8.10.0+24190+49a46c75
  • nodejs-libs RHEL 8 1:24.14.1-2.module+el8.10.0+24190+49a46c75
  • nodejs-nodemon RHEL 8 3.0.3-1.module+el8.10.0+24190+49a46c75

red hat advisories RHSA-2026:7675RHSA-2026:7670RHSA-2026:7350

  • nodejs24 SLES for SAP applications 16.0, SLES 16.0 24.18.0-160000.1.1
  • nodejs24 SLE Module for Web and Scripting 15 SP7 24.17.0-150700.15.11.1

suse advisories SUSE-SU-2026:22565-1SUSE-SU-2026:2633-1

  • nodejs24 openSUSE Leap 16.0 24.18.0-160000.1.1
  • nodejs24 openSUSE Tumbleweed 24.17.0-1.1

opensuse advisories openSUSE-SU-2026:21236-1openSUSE-SU-2026:11121-1

  • npm AlmaLinux 8 1:11.11.0-1.24.14.1.2.module_el8.10.0+4160+4819ac42
  • nodejs AlmaLinux 8 1:24.14.1-2.module_el8.10.0+4160+4819ac42
  • nodejs-libs AlmaLinux 8 1:24.14.1-2.module_el8.10.0+4160+4819ac42
  • nodejs-nodemon AlmaLinux 8 3.0.3-1.module_el8.10.0+4061+f8ceeab9
  • nodejs-full-i18n AlmaLinux 8 1:24.14.1-2.module_el8.10.0+4160+4819ac42
  • nodejs-packaging AlmaLinux 8 2021.06-6.module_el8.10.0+4086+70facd4a
  • nodejs-packaging-bundler AlmaLinux 8 2021.06-6.module_el8.10.0+4086+70facd4a
  • nodejs24-npm AlmaLinux 10 1:11.11.0-1.24.14.1.2.el10_1

almalinux advisories ALSA-2026:7670ALSA-2026:7675ALSA-2026:7350

  • nodejs24 Rocky Linux 10 1:24.14.1-2.el10_1
  • nodejs-nodemon Rocky Linux 8 3.0.3-1.module+el8.10.0+2084+ab509703
  • nodejs-packaging Rocky Linux 8 2021.06-6.module+el8.10.0+40048+6d99f608
  • nodejs-nodemon Rocky Linux 9 3.0.3-3.module+el9.7.0+40025+0e0cf6b2
  • nodejs-packaging Rocky Linux 9 2021.06-6.module+el9.7.0+40052+e32ea525

rocky linux advisories RLSA-2026:7675RLSA-2026:7670RLSA-2026:7350

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-2026-2581 updated cvss 5.9

undici: Undici: Denial of Service due to uncontrolled resource consumption

  • Red Hat Cryostat 4 io.cryostat-cryostat Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-console-plugin-rhel9, openshift-lightspeed/lightspeed-console-plugin-pf5-rhel9 Red Hat OpenShift Pipelines openshift-pipelines/pipelines-console-plugin-rhel8, openshift-pipelines/pipelines-console-plugin-rhel9 Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9, rhdh/backstage-community-plugin-catalog-backend-module-scaffolder-relation-processor Red Hat Enterprise Linux 8 npm, nodejs, nodejs-libs, nodejs-nodemon, nodejs-full-i18n, nodejs-packaging, +1 more Red Hat Enterprise Linux 9 npm, nodejs, nodejs-libs, nodejs-full-i18n
    +6 more products
    Red Hat Enterprise Linux 10 nodejs22 Red Hat JBoss Enterprise Application Platform 8 org.keycloak-keycloak-parent Red Hat JBoss Enterprise Application Platform Expansion Pack org.keycloak-keycloak-parent Red Hat OpenShift AI (RHOAI) rhoai/odh-dashboard-rhel8, rhoai/odh-pipeline-runtime-minimal-cpu-py312-rhel9, rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9, rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9, rhoai/odh-workbench-jupyter-minimal-cpu-py312-rhel9, rhoai/odh-workbench-jupyter-minimal-cuda-py312-rhel9, +13 more Red Hat OpenShift Dev Spaces devspaces/code-rhel9, devspaces/openvsx-rhel9, devspaces/code-sshd-rhel9 Red Hat Self-service automation portal 2 ansible-automation-platform/automation-portal
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 8) nodejs 24.14.1-2.module+el8.10.0+24190+49a46c75, nodejs-libs 24.14.1-2.module+el8.10.0+24190+49a46c75, nodejs-nodemon 3.0.3-1.module+el8.10.0+24190+49a46c75, npm 11.11.0-1.24.14.1.2.module+el8.10.0+24190+49a46c75, nodejs-full-i18n 24.14.1-2.module+el8.10.0+24190+49a46c75, nodejs-packaging 2021.06-6.module+el8.10.0+24190+49a46c75, +1 more
    fixed: vendor fix RHSA-2026:7670
  • Red Hat Enterprise Linux AppStream (v. 9) nodejs 24.14.1-2.module+el9.7.0+24166+51c9666b, nodejs-libs 24.14.1-2.module+el9.7.0+24166+51c9666b, nodejs-nodemon 3.0.3-3.module+el9.7.0+24166+51c9666b, npm 11.11.0-1.24.14.1.2.module+el9.7.0+24166+51c9666b, nodejs-full-i18n 24.14.1-2.module+el9.7.0+24166+51c9666b, nodejs-packaging 2021.06-6.module+el9.7.0+24166+51c9666b, +1 more
    fixed: vendor fix RHSA-2026:7350
  • Red Hat Enterprise Linux AppStream (v. 10) nodejs24 24.14.1-2.el10_1, nodejs24-libs 24.14.1-2.el10_1, nodejs24-full-i18n 24.14.1-2.el10_1, nodejs24-npm 11.11.0-1.24.14.1.2.el10_1
    fixed: vendor fix RHSA-2026:7675

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
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm undici
>=7.17.0, <7.24.0
7.24.0

Affected products

  • undici undici

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

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.