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CVE-2026-88049— Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch

Quick assessment

Affected
tesseract-ocr tesseract
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Tesseract 是一个开源的光学字符识别（OCR）引擎。在 5.5.3 及更早的版本中，针对 .traineddata 文件进行的加固工作曾在 中的 和 函数中添加了边界检查，但遗漏了对 和 函数的检查。 在 的 函数中， 的大小由独立反序列化的 字段决定，而 使用的计数值 则来源于 CI 门控中 的 值。一个经过精心构造的 层可以使 远大于 ，从而在默认 LSTM 引擎执行首次识别步骤时，触发堆内存越界写入，导致堆内存损坏、程序崩溃，甚至可能引发受控的内存破坏。 截至本次安全审查时，尚未发布包含修复的正式版本

CVSS 8.6 · High

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application
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I. Basic Information for CVE-2026-88049

Vulnerability Information
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Vulnerability Title
Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
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
Source: CVE Program / CVE List V5
Vulnerability Type
跨界内存写
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
tesseract-ocr tesseract <= 5.5.3 -

II. Public POCs for CVE-2026-88049

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III. Intelligence Information for CVE-2026-88049

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Patches & Fixes for CVE-2026-88049 (1)

Vendor Advisories for CVE-2026-88049 (1)

Same Patch Batch · tesseract-ocr · 2026-09-10 · 8 CVEs total

CVE-2026-88048 8.6 HIGH Tesseract: Heap out-of-bounds write/read in FullyConnected::Forward via layer/weight-matri
CVE-2026-88047 8.6 HIGH Tesseract: ReadNormProtos stack buffer overflow
CVE-2026-88051 8.6 HIGH Tesseract: Heap out-of-bounds write in GenericVector<T>::read due to independent reserved/
CVE-2026-88053 8.6 HIGH Tesseract: Heap out-of-bounds write in Classify::ReadIntTemplates via unvalidated counts i
CVE-2026-88052 7.8 HIGH Tesseract: Heap out-of-bounds write in UNICHARSET::load_via_fgets via count/insert desynch
CVE-2026-88050 6.9 MEDIUM Tesseract: Out-of-bounds write in UnicharCompress via unvalidated recoder code values
CVE-2026-88054 6.9 MEDIUM Tesseract: Denial of service via empty-stack dereference in Plumbing/Series at model load

IV. Related Vulnerabilities

Same product: tesseract
Same vendor: tesseract-ocr
Same weakness: CWE-787

V. Comments for CVE-2026-88049

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