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CVE Record

CVE-2026-46384: iskorotkov/avro: Integer Overflow in Avro Decoder

iskorotkov/avro is a fast Go Avro codec. Prior to 2.33.0, several Avro decoder paths read attacker-controlled 64-bit values from the wire format and either narrowed them to platform-sized int before bounds-checking, or summed them with overflow-prone signed-int arithmetic. On 32-bit targets (GOARCH=386, arm, mips, wasm, etc.), the truncation paths can silently bypass byte-slice limits, select the wrong union branch, or hit the OCF negative-make panic via wrap. Three sub-issues are not 32-bit-specific: cumulative-size arithmetic overflow in arrayDecoder.Decode / mapDecoder.Decode / mapDecoderUnmarshaler.Decode (wraps at math.MaxInt64 on amd64 / arm64 and bypasses MaxSliceAllocSize / MaxMapAllocSize), math.MinInt negation in block-header handling, and make([]byte, size) with a negative size in OCF block reads — all three panic or bypass caps on any platform, giving an attacker a denial-of-service primitive there. This vulnerability is fixed in 2.33.0.

HighCVSS 8.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A remote attacker who can supply crafted Avro data may crash a service, causing denial of service. Some 32-bit deployments also risk decoder safety checks being bypassed or incorrect union selection. Several crash and allocation-limit bypass conditions affect 64-bit systems too. The issue is fixed in version 2.33.0.

Executive priority

Treat this as a high-priority availability risk for exposed data-processing services. Accelerate remediation where untrusted parties can submit Avro or OCF content, especially for critical or multi-tenant workloads. Do not defer solely because production uses 64-bit systems; documented platform-independent paths remain.

Technical view

Before 2.33.0, decoder paths narrow attacker-controlled 64-bit values to int or use overflow-prone signed arithmetic. Results include bounds and allocation-cap bypasses, incorrect union selection, math.MinInt negation, and negative-size allocation panics. Extra truncation issues affect 32-bit targets; cumulative-size overflow and certain OCF block failures also affect 64-bit targets.

Likely exposure

Exposure exists where applications use iskorotkov/avro before 2.33.0 and decode untrusted Avro or OCF data. Internet-facing ingestion, messaging, file-processing, and multi-tenant services merit priority. Although 32-bit targets have additional paths, amd64 and arm64 deployments are not exempt from denial-of-service risk.

Exploitation context

The CVSS 4.0 score is 8.7, with network access, low complexity, no privileges, and no user interaction indicated. The supplied record is not in KEV and provides no evidence of active exploitation. Practical impact depends on whether an attacker can reach an application path that decodes crafted Avro or OCF input.

Researcher notes

Review arrayDecoder.Decode, mapDecoder.Decode, mapDecoderUnmarshaler.Decode, union selection, block-header processing, and OCF block reads. Separate 32-bit narrowing defects from platform-independent signed-overflow and negative-allocation cases. The supplied evidence supports denial of service and cap bypasses, but does not establish active exploitation or broader confidentiality impact.

Mitigation direction

  • Upgrade iskorotkov/avro to version 2.33.0 or later.
  • Prioritize internet-facing and multi-tenant services that decode untrusted Avro or OCF data.
  • Apply relevant Red Hat errata where the vulnerable library is supplied through affected Red Hat products.
  • Until upgraded, restrict untrusted Avro and OCF inputs and monitor decoder panics or abnormal restarts.

Validation and detection

  • Inventory Go applications and dependency manifests for iskorotkov/avro versions earlier than 2.33.0.
  • Identify workloads decoding attacker-controlled Avro or OCF data, including asynchronous ingestion paths.
  • Record target GOARCH; 32-bit builds have additional truncation exposure, while some denial-of-service paths affect 64-bit systems.
  • Confirm deployed artifacts resolve version 2.33.0 or later after remediation.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-190: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-46384 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.7 (4.0)
Known Exploited
No
Published

Vector: 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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
15Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.7CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——GitHub_M
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

8.7High
CVSS 4.0 vector shape for CVE-2026-46384Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: 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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPgithub.com/hamba/avro/v2: github.com/linkedin/goavro/v2: Integer Overflow in Avro Decoder
other:Red Hat severity ratingcvssV3_1
  • 2026-05-29T21:02:03.061Z: Reported to Red Hat.
  • 2026-05-29T19:58:21.535Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
iskorotkovavro< 2.33.0Listed
Weakness

CWE details

CWE-190

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-190 · source CWE mapping

Integer Overflow or Wraparound

Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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