Heap Exhaustion via Unvalidated Len in Prometheus Remote Read (<3.5.3/3.11.3)
CVE-2026-42154 Published on May 4, 2026

Prometheus: remote read endpoint allows denial of service via crafted snappy payload
Prometheus is an open-source monitoring system and time series database. Prior to versions 3.5.3 and 3.11.3, the remote read endpoint (/api/v1/read) does not validate the declared decoded length in a snappy-compressed request body before allocating memory. An unauthenticated attacker can send a small payload that causes a huge heap allocation per request. Under concurrent load this can exhaust available memory and crash the Prometheus process. This issue has been patched in versions 3.5.3 and 3.11.3.

NVD

Vulnerability Analysis

CVE-2026-42154 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Types

What is a Resource Exhaustion Vulnerability?

The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

CVE-2026-42154 has been classified to as a Resource Exhaustion vulnerability or weakness.

What is a Stack Exhaustion Vulnerability?

The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.

CVE-2026-42154 has been classified to as a Stack Exhaustion vulnerability or weakness.

Allocation of Resources Without Limits or Throttling

The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.


Products Associated with CVE-2026-42154

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-42154 are published in these products:

Prometheus
 
Red Hat Acm
 
Red Hat Hummingbird
 
Red Hat Openshift File Integrity Operator
 
Red Hat Logging
 
Red Hat Multicluster Globalhub
 
Red Hat Network Observ Optr
 
Red Hat Openshift Lightspeed
 
Red Hat Ceph Storage
 
Red Hat Edge Manager
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Openshift Ai
 
Red Hat Openshift
 
Red Hat Openshift Gitops
 
Red Hat Quay
 
Red Hat Trusted Artifact Signer
 
Red Hat Service Mesh
 
Red Hat Openstack
 

Affected Versions

prometheus: Red Hat RHEM 1.0 for RHEL 9: Red Hat Enterprise Linux AppStream (v. 10): Red Hat Enterprise Linux AppStream (v. 9): Logging Subsystem for Red Hat OpenShift 6.4: Red Hat Advanced Cluster Management for Kubernetes 2.13: Red Hat Edge Manager 1.0: Red Hat Hardened Images: Red Hat OpenShift Container Platform 4.22: Red Hat File Integrity Operator: Logging Subsystem for Red Hat OpenShift: Red Hat Multicluster Global Hub: Red Hat Network Observability Operator: Red Hat OpenShift Lightspeed: Red Hat Ceph Storage 5: Red Hat Ceph Storage 6: Red Hat Ceph Storage 7: Red Hat Ceph Storage 8: Red Hat Ceph Storage 9: Red Hat Edge Manager 1: Red Hat OpenShift AI (RHOAI): Red Hat OpenShift Container Platform 4: Red Hat OpenShift GitOps: Red Hat Quay 3: Red Hat Trusted Artifact Signer: Red Hat OpenShift Service Mesh 2: Red Hat OpenShift Service Mesh 3: Red Hat Advanced Cluster Management for Kubernetes 2: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat OpenStack Platform 18.0:

Exploit Probability

EPSS
0.56%
Percentile
42.07%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.