Tesseract is an open source OCR engine. In version 5.5.3 and earlier, prior .traineddata hardening added bounds checks to NetworkIO::CopyTimeStepGeneral and NetworkIO::Randomize in src/lstm/networkio.cpp but left NetworkIO::WriteTimeStepPart and NetworkIO::AddTimeStepPart unchecked. In LSTM::Forward in src/lstm/lstm.cpp, source_ is sized from the independently deserialized na_ field while the WriteTimeStepPart count is ns_, which comes from the CI gate WeightMatrix dim1() value. A crafted NT_LSTM layer can make ns_ much larger than na_, causing a heap out-of-bounds write during the first recognition step on the default LSTM engine and resulting in heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.
History

Mon, 14 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Tesseract-ocr
Tesseract-ocr tesseract Ocr
CPEs cpe:2.3:a:tesseract-ocr:tesseract_ocr:*:*:*:*:*:*:*:*
Vendors & Products Tesseract-ocr
Tesseract-ocr tesseract Ocr
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Sun, 13 Sep 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Tesseract Project
Tesseract Project tesseract
Vendors & Products Tesseract Project
Tesseract Project tesseract

Fri, 11 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

threat_severity

Important


Thu, 10 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 10 Sep 2026 16:45:00 +0000

Type Values Removed Values Added
Description Tesseract is an open source OCR engine. In version 5.5.3 and earlier, prior .traineddata hardening added bounds checks to NetworkIO::CopyTimeStepGeneral and NetworkIO::Randomize in src/lstm/networkio.cpp but left NetworkIO::WriteTimeStepPart and NetworkIO::AddTimeStepPart unchecked. In LSTM::Forward in src/lstm/lstm.cpp, source_ is sized from the independently deserialized na_ field while the WriteTimeStepPart count is ns_, which comes from the CI gate WeightMatrix dim1() value. A crafted NT_LSTM layer can make ns_ much larger than na_, causing a heap out-of-bounds write during the first recognition step on the default LSTM engine and resulting in heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.
Title Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch
Weaknesses CWE-787
References
Metrics cvssV4_0

{'score': 8.6, 'vector': '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-09-10T16:23:18.718Z

Updated: 2026-09-10T17:13:02.365Z

Reserved: 2026-09-09T21:22:45.433Z

Link: CVE-2026-88049

cve-icon Vulnrichment

Updated: 2026-09-10T17:12:54.829Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-10T17:17:09.087

Modified: 2026-09-14T20:01:48.403

Link: CVE-2026-88049

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-10T16:23:18Z

Links: CVE-2026-88049 - Bugzilla