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Uncontrolled Resource ConsumptionWeakness · CWE-400

CVE-2026-46385

HIGH · 7.5 CVSS v3.1 Published 2026-05-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The iskorotkov/avro Go library versions prior to 2.33.0 contain a denial-of-service vulnerability in Avro array and map decoders. The decoder loops over an attacker-controlled block-count value from Reader.ReadBlockHeader without checking the underlying reader's error state inside the loop body. Since ReadBlockHeader returns count as a 64-bit int, a malicious producer can declare up to math.MaxInt64 elements, causing the decoder to attempt billions of no-op iterations before propagating any error, effectively pinning a CPU core until the process is OOM-killed, deadline-cancelled, or terminated.

MitigationUpgrade to iskorotkov/avro version 2.33.0 or later, which includes proper error checking within the decoder loop to prevent this DoS vector.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate iskorotkov/avro in your codebase
    Search your go.mod file or run 'go list -m all | grep avro' to find the iskorotkov/avro package and its version
    Affected if The package is present with a version lower than 2.33.0
  2. Verify the exact version number
    Inspect your go.mod file for the version after 'iskorotkov/avro' (e.g., 'iskorotkov/avro v2.32.0') or run 'go list -m -json iskorotkov/avro' to retrieve the version field
    Affected if Version is listed as anything below 2.33.0 (e.g., 2.32.0, 2.31.0, etc.)
  3. Confirm Avro deserialization is in use
    Search your codebase for usage of avro.NewDecoder, avro.Decoder, or any type that decodes Avro data (particularly reading from untrusted sources)
    Affected if Code deserializes Avro data from potentially untrusted producers using array or map types
  4. Identify array and map decoding paths
    Review code that decodes Avro records containing array or map fields, as these trigger the vulnerable decoder loops
    Affected if Your application decodes Avro schemas with array or map fields from external sources

You are affected if you use iskorotkov/avro version below 2.33.0 and decode Avro data from untrusted sources containing array or map structures.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to iskorotkov/avro version 2.33.0 or later, which includes proper error checking within the decoder loop to prevent this DoS vector.

Recommended fix High confidence

v2.33.0

  1. Identify all applications and services that import the iskorotkov/avro Go library (e.g., search go.mod files, dependency scans)
  2. Check the current version of iskorotkov/avro in use (run 'go list -m all' or inspect go.mod)
  3. Upgrade to version 2.33.0 or later (run 'go get github.com/iskorotkov/[email protected]' or 'go get github.com/iskorotkov/avro@latest')
  4. Run 'go mod tidy' to update go.sum and remove unused dependencies
  5. Verify the upgrade by running 'go list -m github.com/iskorotkov/avro' to confirm the installed version
  6. Run existing test suites to ensure the upgrade does not break functionality
  7. Redeploy updated services to production
Caveat Check release notes for v2.33.0 for any breaking changes; minor version upgrades in Go libraries are typically low-risk but test verification is recommended

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-46385 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data