---
id: CVE-2026-88049
title: Tesseract is an open source OCR engine
summary: >-
  Tesseract is an open source OCR engine. In version 5.5.3 and earlier, prior
  .traineddata hardening added bounds checks to NetworkIO::CopyTimeStepGeneral
  and NetworkIO::Randomize in src/lstm/networkio.cpp but left
  NetworkIO::WriteTimeStep…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-787
vendor: tesseract-ocr
product: tesseract_ocr
affected:
  - tesseract_ocr <= 5.5.3
published: '2026-09-10'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T20:01:48.403'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88049'
references:
  - url: >-
      https://github.com/tesseract-ocr/tesseract/commit/b494ac18925f9d9aff9ef5815475de9943ab19bf
    label: security-advisories@github.com
  - url: >-
      https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-jgq8-pprg-vc68
    label: security-advisories@github.com
  - url: >-
      https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-jgq8-pprg-vc68
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88049.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-88049'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2531554'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-88049'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88049'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00144
epssPercentile: 0.03057
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-10T17:12:06.792549Z'
scores:
  nvd: 5.5
  cna: 8.6
  vendor: 7.8
ingestedAt: '2026-09-13T09:25:55.014Z'
---

## Overview

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, prior .traineddata hardening added bounds checks to NetworkIO::CopyTimeStepGeneral and NetworkIO::Randomize in src/lstm/networkio.cpp but left NetworkIO::WriteTimeStepPart and NetworkIO::AddTimeStepPart unchecked. In LSTM::Forward in src/lstm/lstm.cpp, source_ is sized from the independently deserialized na_ field while the WriteTimeStepPart count is ns_, which comes from the CI gate WeightMatrix dim1() value. A crafted NT_LSTM layer can make ns_ much larger than na_, causing a heap out-of-bounds write during the first recognition step on the default LSTM engine and resulting in heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.

## Affected

- `tesseract_ocr <= 5.5.3`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-88049.json)