# CVE-2026-88051: Tesseract: Heap out-of-bounds write in GenericVector<T>::read due to independent reserved/size_used_ fields

> A heap out-of-bounds write in Tesseract allows attackers to cause crashes or potentially execute code via crafted traineddata files.

- **Severity:** High 8.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-88051, ECHO-09e7-889a-f5d7, GHSA-88qp-4g94-3rf3, UBUNTU-CVE-2026-88051

## What is CVE-2026-88051?

CVE-2026-88051 is a high-severity memory corruption vulnerability in tesseract-ocr tesseract, published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, the callback form of GenericVector::read in src/ccutil/genericvector.h reads the independent int32 fields reserved and size_used_ from a .traineddata model without a cap or an invariant check. reserve(reserved) allocates the backing array, but the callback loop writes size_used_ elements. A crafted TESSDATA_INTTEMP component with version_id 4 or later can therefore set reserved to a small value and size_used_ to a large value when fontinfo_table_.read(fp, read_info) is called from src/classify/intproto.cpp, causing a heap out-of-bounds write of FontInfo structures, heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-88051?

It affects 1 product.


Products: Tesseract-Ocr Tesseract Ocr.

## How do I fix CVE-2026-88051?

No fix published yet.

## Is CVE-2026-88051 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88051 exists.

## Other vulnerabilities in tesseract-ocr tesseract

- [CVE-2026-88047](https://insights.sbomify.com/CVE-2026-88047/): Tesseract: ReadNormProtos stack buffer overflow (high 8.6)
- [CVE-2026-88048](https://insights.sbomify.com/CVE-2026-88048/): Tesseract: Heap out-of-bounds write/read in FullyConnected::Forward via layer/weight-matrix dimension mismatch (high 8.6)
- [CVE-2026-88049](https://insights.sbomify.com/CVE-2026-88049/): Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch (high 8.6)
- [CVE-2026-88053](https://insights.sbomify.com/CVE-2026-88053/): Tesseract: Heap out-of-bounds write in Classify::ReadIntTemplates via unvalidated counts in crafted .traineddata (high 8.6)
- [CVE-2026-88052](https://insights.sbomify.com/CVE-2026-88052/): Tesseract: Heap out-of-bounds write in UNICHARSET::load_via_fgets via count/insert desynchronization (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88051 and fix it if it is affected.

What it is: CVE-2026-88051 is a high-severity memory corruption vulnerability in tesseract-ocr tesseract, published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88051 exists.

Affected product: tesseract-ocr tesseract. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-88051/ (Markdown: https://insights.sbomify.com/CVE-2026-88051/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88051
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88051
- OSV: https://osv.dev/vulnerability/CVE-2026-88051

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-88051/
Summaries are generated and may contain mistakes; the official description above is the record.