Tesseract: Out-of-bounds write in UnicharCompress via unvalidated recoder code values (CVE-2026-88050) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-88050

Tesseract: Out-of-bounds write in UnicharCompress via unvalidated recoder code values

Answer in brief

CVE-2026-88050 records a Unknown severity vulnerability in Tesseract: Out-of-bounds write in UnicharCompress via unvalidated recoder code values. The current sources do not mark it as known exploited. The current feed maps tesseract-ocr/tesseract (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 10, 2026Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Sep 10, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps tesseract-ocr/tesseract (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
tesseract-ocr/tesseractgeneric	<= 5.5.3	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for tesseract-ocr/tesseract.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 10, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 10, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.