CVE-2026-88048 Tesseract: Heap out-of-bounds write/read in FullyConnected::Forward via layer/weight-matrix dimension mismatch
A crafted traineddata file can trigger heap out-of-bounds write and read in Tesseract's LSTM engine, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-88048?
CVE-2026-88048 is a high-severity memory corruption vulnerability in tesseract-ocr tesseract, published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Tesseract is an open source OCR engine. In version 5.5.3 and earlier, FullyConnected::DeSerialize in src/lstm/fullyconnected.cpp does not validate the deserialized layer scalars ni_ and no_ against the weight-matrix dimensions. During FullyConnected::Forward, MatrixDotVector in src/lstm/weightmatrix.cpp writes w.dim1() results into temp_line, which is sized from no_, and reads w.dim2() minus one inputs from curr_input, which is sized from ni_. A crafted .traineddata NT_SOFTMAX layer can therefore use inconsistent dimensions to cause a heap out-of-bounds write and read on the default LSTM engine, resulting in heap corruption, a crash, information disclosure, or potentially controlled corruption. No fixed release is available as of this review.
Which versions are affected by CVE-2026-88048?
It affects 1 product.
Products include Tesseract-Ocr Tesseract Ocr.
How do I fix CVE-2026-88048?
No fix published yet.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-88048 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88048 exists.
Other vulnerabilities in tesseract-ocr tesseract
- CVE-2026-88047 Tesseract: ReadNormProtos stack buffer overflow
- CVE-2026-88049 Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch
- CVE-2026-88051 Tesseract: Heap out-of-bounds write in GenericVector<T>::read due to independent reserved/size_used_ fields
- CVE-2026-88053 Tesseract: Heap out-of-bounds write in Classify::ReadIntTemplates via unvalidated counts in crafted .traineddata
- CVE-2026-88052 Tesseract: Heap out-of-bounds write in UNICHARSET::load_via_fgets via count/insert desynchronization
Sources
Also known as DEBIAN-CVE-2026-88048, ECHO-18ac-cecc-73b2, GHSA-q44c-23p6-5mw6, UBUNTU-CVE-2026-88048.