# CVE-2026-88054: libtesseract4: Tesseract is an open source OCR engine

CVE-2026-88054 is fixed in 19 products on 1 platform, first by libtesseract5 5.5.0-1ubuntu0.1~esm1, released September 10, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-88054
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0015
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 10, 2026

## Description

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, Plumbing::DeSerialize in src/lstm/plumbing.cpp rejects excessively large network stacks but accepts a zero-length stack for NT_SERIES, NT_PARALLEL, or NT_REVERSED layers in a crafted .traineddata model. During LSTMRecognizer initialization in src/lstm/lstmrecognizer.cpp, CacheXScaleFactor(XScaleFactor()) reaches Series::CacheXScaleFactor in src/lstm/series.cpp, which dereferences stack_[0] on the empty vector and invokes a virtual method through an invalid Network pointer. This causes a deterministic crash and denial of service at model load. No fixed release is available as of this review.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libtesseract4 Ubuntu 18.04.6 LTS (bionic) | 4.00~git2288-10f4998a-2ubuntu0.1~esm1 | [libtesseract4 4.00~git2288-10f4998a-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libtesseract4-4.00-git2288-10f4998a-2ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | libtesseract4 Ubuntu 20.04 LTS (focal) | 4.1.1-2ubuntu0.1~esm1 | [libtesseract4 4.1.1-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libtesseract4-4.1.1-2ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | libtesseract4 Ubuntu 22.04.1 LTS (jammy) | 4.1.1-2.1ubuntu0.1~esm1 | [libtesseract4 4.1.1-2.1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libtesseract4-4.1.1-2.1ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | libtesseract5 Ubuntu 24.04.5 LTS (noble) | 5.3.4-1ubuntu0.1~esm1 | [libtesseract5 5.3.4-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libtesseract5-5.3.4-1ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | libtesseract5 Ubuntu 26.04.1 LTS (resolute) | 5.5.0-1ubuntu0.1~esm1 | [libtesseract5 5.5.0-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libtesseract5-5.5.0-1ubuntu0.1-esm1.md) | Sep 10, 2026 |
| Linux | mingw32-tesseract Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | mingw32-tesseract-debuginfo Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | mingw32-tesseract-tools Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | mingw64-tesseract Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | mingw64-tesseract-debuginfo Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | mingw64-tesseract-tools Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-common Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-debuginfo Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-debugsource Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-devel Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-libs Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-libs-debuginfo Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-ocr Ubuntu 18.04.6 LTS (bionic) | 4.00~git2288-10f4998a-2ubuntu0.1~esm1 | [tesseract-ocr 4.00~git2288-10f4998a-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-tesseract-ocr-4.00-git2288-10f4998a-2ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr Ubuntu 20.04 LTS (focal) | 4.1.1-2ubuntu0.1~esm1 | [tesseract-ocr 4.1.1-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-tesseract-ocr-4.1.1-2ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr Ubuntu 22.04.1 LTS (jammy) | 4.1.1-2.1ubuntu0.1~esm1 | [tesseract-ocr 4.1.1-2.1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-tesseract-ocr-4.1.1-2.1ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr Ubuntu 24.04.5 LTS (noble) | 5.3.4-1ubuntu0.1~esm1 | [tesseract-ocr 5.3.4-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-tesseract-ocr-5.3.4-1ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr Ubuntu 26.04.1 LTS (resolute) | 5.5.0-1ubuntu0.1~esm1 | [tesseract-ocr 5.5.0-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-tesseract-ocr-5.5.0-1ubuntu0.1-esm1.md) | Sep 10, 2026 |
| Linux | tesseract-ocr opensuse-leap 16.0 | 5.5.3-bp160.1.1 | [OPENSUSE-SU-2026:21957-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21957-1.md) | Sep 24, 2026 |
| Linux | tesseract-ocr-all Ubuntu 18.04.6 LTS (bionic) | 4.00~git2288-10f4998a-2ubuntu0.1~esm1 | [tesseract-ocr-all 4.00~git2288-10f4998a-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-tesseract-ocr-all-4.00-git2288-10f4998a-2ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr-all Ubuntu 20.04 LTS (focal) | 4.1.1-2ubuntu0.1~esm1 | [tesseract-ocr-all 4.1.1-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-tesseract-ocr-all-4.1.1-2ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr-all Ubuntu 22.04.1 LTS (jammy) | 4.1.1-2.1ubuntu0.1~esm1 | [tesseract-ocr-all 4.1.1-2.1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-tesseract-ocr-all-4.1.1-2.1ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr-all Ubuntu 24.04.5 LTS (noble) | 5.3.4-1ubuntu0.1~esm1 | [tesseract-ocr-all 5.3.4-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-tesseract-ocr-all-5.3.4-1ubuntu0.1-esm1.md) | Oct 7, 2026 |
| Linux | tesseract-ocr-all Ubuntu 26.04.1 LTS (resolute) | 5.5.0-1ubuntu0.1~esm1 | [tesseract-ocr-all 5.5.0-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-tesseract-ocr-all-5.5.0-1ubuntu0.1-esm1.md) | Sep 10, 2026 |
| Linux | tesseract-tools Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |
| Linux | tesseract-tools-debuginfo Fedora 43 | 5.5.3-2.fc43 | [FEDORA-2026-4585ABA520](https://patchblox.com/security/data/fix/linux/fedora-2026-4585aba520.md) | Sep 21, 2026 |

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Data as of 2026-11-09T19:38:12Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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