---
id: CVE-2026-88345
title: >-
  An out-of-bounds read vulnerability exists in the schema lexer of flatcc
  4c3b999e
summary: >-
  An out-of-bounds read vulnerability exists in the schema lexer of flatcc
  4c3b999e. When an exact-length FlatBuffers schema ends with an unterminated
  quotation mark, the C-string scanning logic in lex() dereferences the input
  pointer afte…
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-125
published: '2026-09-22'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:08:55.030'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88345'
references:
  - url: 'https://github.com/dvidelabs/flatcc/issues/385'
    label: cve@mitre.org
  - url: >-
      https://github.com/jimjag/flatcc/commit/8581715e8ec4e5de8eea9fd6dad949e4dd7d0fa0
    label: cve@mitre.org
  - url: 'https://github.com/dvidelabs/flatcc/issues/385'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00415
epssPercentile: 0.33033
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T15:09:43.563884Z'
ingestedAt: '2026-09-22T20:10:15.098Z'
---

## Overview

An out-of-bounds read vulnerability exists in the schema lexer of flatcc 4c3b999e. When an exact-length FlatBuffers schema ends with an unterminated quotation mark, the C-string scanning logic in lex() dereferences the input pointer after it has reached the end of the buffer. A specially crafted schema can trigger a one-byte heap buffer over-read, resulting in application crash and denial of service.

## Remediation

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