---
id: CVE-2026-116734
title: flatcc through 0.6.4 Out-of-Bounds Read via verifier check_header
summary: >-
  flatcc through 0.6.4 contains an integer overflow vulnerability in the
  check_header function of the FlatBuffers verifier because its overflow guard
  is dead code. On 32-bit builds, attackers can supply a crafted buffer offset
  that wraps t…
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-190
vendor: dvidelabs
product: flatcc
affected:
  - flatcc <= 0.6.4
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-27T13:42:01.742265Z'
published: '2026-10-26'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T14:17:08.680Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-116734'
references:
  - url: >-
      https://github.com/dvidelabs/flatcc/commit/0df9c097a19badc8bd22d93af8fd47bd291e5d9f
    label: Patch Commit
  - url: 'https://github.com/dvidelabs/flatcc'
  - url: >-
      https://github.com/dvidelabs/flatcc/blob/v0.6.4/src/runtime/verifier.c#L126-L137
  - url: 'https://hackmd.io/@haindpwn/flatcc-json-number-oob-read'
  - url: >-
      https://www.vulncheck.com/advisories/flatcc-through-0.6.4-out-of-bounds-read-via-verifier-check-header
    label: >-
      VulnCheck Advisory: flatcc through 0.6.4 Out-of-Bounds Read via verifier
      check_header
tags:
  - cve.org
epss: 0.00382
epssPercentile: 0.32039
ingestedAt: '2026-10-27T16:11:59.454Z'
---

## Overview

flatcc through 0.6.4 contains an integer overflow vulnerability in the check_header function of the FlatBuffers verifier because its overflow guard is dead code. On 32-bit builds, attackers can supply a crafted buffer offset that wraps the bounds check, causing an out-of-bounds read before the buffer and crashing the process.

## Affected

- `flatcc <= 0.6.4`

## Remediation

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