CyberSecBulletin
CVE-2026-46385NVD status: Deferred

avro: Uncontrolled Resource Consumption

Published Updated By the CyberSecBulletin desk

CVE-2026-46385 is a high-severity uncontrolled resource consumption vulnerability in avro from Iskorotkov, 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. Affected avro versions: < 2.33.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.61% chance of exploitation within 30 days, higher than 50% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of avro you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com 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
Iskorotkovavro< 2.33.0Not stated
Red HatCryostat 4 on RHEL 9Not specified in the recordNot stated
Red HatMulticluster Global Hub 1.4.5Not specified in the recordNot stated
Red HatMulticluster Global Hub 1.6.5Not specified in the recordNot stated
Red HatMulticluster Global Hub 1.7.0Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.11Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.13Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.16Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.17Not specified in the recordNot stated
Red HatRed Hat multicluster global hub 1.5.3Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 10Not 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 Hardened ImagesNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. 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 4.08.7HighCNA (github.com)
CVSS 3.17.5HighCNA

Official description

iskorotkov/avro is a fast Go Avro codec. Prior to 2.33.0, the Avro array and map decoders looped over an attacker-controlled block-count value without checking the underlying reader's error state inside the loop body. Reader.ReadBlockHeader returns the count as a Go int, which is 64-bit on amd64 / arm64 targets — so a producer can declare a block of up to math.MaxInt64 (~9.2 × 10¹⁸) elements followed by EOF (or any truncated payload), and the decoder will attempt that many no-op iterations before propagating the error. The realistic ceiling is "indefinite until the worker is killed externally" — a single hostile payload pins a CPU core until the process is OOM-killed, deadline-cancelled, or terminated. Remote, unauthenticated denial-of-service. This vulnerability is fixed in 2.33.0.

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: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in avro

All avro vulnerabilities

Recent Uncontrolled Resource Consumption vulnerabilities

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