CyberSecBulletin
CVE-2026-12151NVD status: Modified

undici: Uncontrolled Resource Consumption

Published Updated By the CyberSecBulletin desk

CVE-2026-12151 is a high-severity uncontrolled resource consumption vulnerability in undici, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 6.26.0, 7.28.0, 8.5.0 as the first without the flaw, so updating undici to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update undici to 6.26.0 or 7.28.0 or 8.5.0, whichever matches your release line, or a later version.
  2. Read the advisory on cna.openjsf.org for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Undiciundicibefore 6.26.0; 7.0.0 up to, but not including, 7.28.0; 8.0.0 up to, but not including, 8.5.06.26.0, 7.28.0, 8.5.0
Red HatCryostat 4 on RHEL 9Not specified in the recordNot stated
Red HatRed Hat AMQ Broker 7.13.6Not specified in the recordNot stated
Red HatRed Hat AMQ Broker 7.14.1Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 10.0 Extended Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.6 Extended Update SupportNot specified in the recordNot stated
Red HatCluster Observability Operator 1.5.0Not specified in the recordNot stated
Red HatRed Hat Developer Hub 1.10Not specified in the recordNot stated
Red HatRed Hat Developer Hub 1.9Not specified in the recordNot stated
Red HatRed Hat Hardened ImagesNot specified in the recordNot stated
Red HatRed Hat OpenShift AI 2.25Not specified in the recordNot stated
Red HatRed Hat OpenShift AI 3.4Not specified in the recordNot stated
Red HatRed Hat OpenShift Container Platform 4.16Not specified in the recordNot stated
Red HatRed Hat OpenShift Container Platform 4.17Not specified in the recordNot stated
Red HatRed Hat Openshift Data Foundation 4.18Not specified in the recordNot stated
Red HatRed Hat Openshift Data Foundation 4.19Not specified in the recordNot stated
Red HatRed Hat Openshift Data Foundation 4.20Not specified in the recordNot stated
Red HatRed Hat OpenShift Dev Spaces 3.29Not specified in the recordNot stated
Red HatRed Hat OpenShift Dev Spaces 3.30Not specified in the recordNot stated
Red HatCryostat 4Not specified in the recordNot stated
Red HatOpenShift PipelinesNot specified in the recordNot stated
Red HatRed Hat Build of Podman DesktopNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE; 3 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA
CVSS 3.17.5HighCNA

Official description

Impact: The undici WebSocket client enforces maxPayloadSize on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size validation, collectively causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service. Affected applications are those using the undici WebSocket client (new WebSocket(...)) or the WebSocketStream API that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint. All releases starting at undici 6.17.0 are affected. Patches: Upgrade to undici >= 6.26.0, >= 7.28.0, or >= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Uncontrolled Resource Consumption

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

How developers prevent this class of flaw

  • Ensure that protocols have specific limits of scale placed on them.
  • Ensure that all failures in resource allocation place the system into a safe posture.

More Uncontrolled Resource Consumption vulnerabilities (CWE-400)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in undici

All undici vulnerabilities

Recent Uncontrolled Resource Consumption vulnerabilities

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