CVE-2026-46385Public exploitNetwork attack vector

Application denial of service via unchecked block counts

Published May 29, 2026 · Updated May 29, 2026

Denial of service in Ivan Korotkov avro before 2.33.0 allows remote attackers to interrupt applications via crafted Avro blocks. Array and map skip and callback decoders trust Reader.ReadBlockHeader counts and keep iterating after inner decoding records EOF, turning later calls into no-ops. Any network-facing application that decodes untrusted Avro data without an external deadline can have one CPU core pinned until the worker is killed.

CVSS severity8.7
High
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Ivan Korotkov avro before 2.33.0 allows remote attackers to interrupt applications via crafted Avro blocks. Array and map skip and callback decoders trust Reader.ReadBlockHeader counts and keep iterating after inner decoding records EOF, turning later calls into no-ops. Any network-facing application that decodes untrusted Avro data without an external deadline can have one CPU core pinned until the worker is killed.

The record

CVE
CVE-2026-46385
Published
May 29, 2026
Updated
May 29, 2026
Vendor
Ivan Korotkov
Product
avro
Classifications
CWE-1284, CWE-400, CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 29, 2026CVE publishedPublication date reported by the CVE source.
  2. May 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.33.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ivan Korotkov · avroversion=< 2.33.0

Published CVSS scores

7.5redhat-SADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1284Improper Validation of Specified Quantity in Input
CWE-400Uncontrolled Resource Consumption
CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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