CVE-2026-88049

Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch

Published Sep 10, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8882-1 Tesseract vulnerabilities
History
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'}

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

Type Values Removed Values Added
Metrics ssvc

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

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 10, 2026, 5:13 PM
Reserved
Sep 9, 2026, 9:22 PM
Status
Analyzed
Published
Sep 10, 2026, 5:17 PM
Modified
Sep 14, 2026, 8:01 PM
Severity
Important
Public date
Sep 10, 2026, 4:23 PM