High 8.6Published Sep 10, 2026

CVE-2026-88053Tesseract: Heap out-of-bounds write in Classify::ReadIntTemplates via unvalidated counts in crafted .traineddata

Updated under an hour ago (2026-10-19 09:50 UTC)

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Exploited in the last 30 days

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, Classify::ReadIntTemplates in src/classify/intproto.cpp reads NumClassPruners, NumClasses, and NumProtoSets from the TESSDATA_INTTEMP component of a crafted .traineddata file and uses those values as loop bounds without validating them against MAX_NUM_CLASS_PRUNERS, MAX_NUM_CLASSES, and MAX_NUM_PROTO_SETS. The loops store heap pointers into fixed-capacity ClassPruners and ProtoSets arrays in INT_TEMPLATES_STRUCT and INT_CLASS_STRUCT, so an oversized count causes heap out-of-bounds pointer writes during legacy-classifier initialization before OCR begins, resulting in heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.

CVSS: 8.6 HIGH (v4.0, CNA)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
Weakness (CWE): CWE-787
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Sep 11, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

tesseract-ocr tesseract tesseract_ocr:tesseract (from the name)	through 5.5.3	CNA record
tesseract-ocr tesseract_ocr tesseract-ocr:tesseract_ocr	through 5.5.3	NVD

References

https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-rphx-x795-5qjvx-refsource-confirm, exploit, mitigation, vendor-advisory
https://github.com/tesseract-ocr/tesseract/commit/8b0574680f3b22f246ade6a4c8e3029104255c63x-refsource-misc, patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.