---
id: CVE-2020-37280
title: >-
  cbor-sync through 1.0.4 contains a resource exhaustion vulnerability in
  CBOR.decode that trusts declared array and map lengths without checking
  remaining input
summary: >-
  cbor-sync through 1.0.4 contains a resource exhaustion vulnerability in
  CBOR.decode that trusts declared array and map lengths without checking
  remaining input. Remote attackers can supply a tiny crafted CBOR payload
  declaring huge lengt…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-789
vendor: PelionIoT
product: cbor-sync
affected:
  - cbor-sync <= 1.0.4
published: '2026-10-12'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:18:44.867'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-37280'
references:
  - url: 'https://github.com/PelionIoT/cbor-sync'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/PelionIoT/cbor-sync/issues/6'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/PelionIoT/cbor-sync/pull/4'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/cbor-sync-through-1.0.4-memory-exhaustion-via-unchecked-cbor-array-lengths
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.00538
epssPercentile: 0.45093
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-13T16:22:06.815030Z'
ingestedAt: '2026-10-12T22:05:40.349Z'
---

## Overview

cbor-sync through 1.0.4 contains a resource exhaustion vulnerability in CBOR.decode that trusts declared array and map lengths without checking remaining input. Remote attackers can supply a tiny crafted CBOR payload declaring huge lengths to drive billions of iterations, exhausting CPU and process memory.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.