CVE-2026-88051 Tesseract: Heap out-of-bounds write in GenericVector<T>::read due to independent reserved/size_used_ fields
A heap out-of-bounds write in Tesseract allows attackers to cause crashes or potentially execute code via crafted traineddata files.
- 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-2026-88051?
CVE-2026-88051 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, the callback form of GenericVector::read in src/ccutil/genericvector.h reads the independent int32 fields reserved and size_used_ from a .traineddata model without a cap or an invariant check. reserve(reserved) allocates the backing array, but the callback loop writes size_used_ elements. A crafted TESSDATA_INTTEMP component with version_id 4 or later can therefore set reserved to a small value and size_used_ to a large value when fontinfo_table_.read(fp, read_info) is called from src/classify/intproto.cpp, causing a heap out-of-bounds write of FontInfo structures, heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.
Weakness: CWE-787
Which versions are affected by CVE-2026-88051?
It affects 1 product.
Products include Tesseract-Ocr Tesseract Ocr.
How do I fix CVE-2026-88051?
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-2026-88051 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88051 exists.
Other vulnerabilities in tesseract-ocr tesseract
- CVE-2026-88047 Tesseract: ReadNormProtos stack buffer overflow
- CVE-2026-88048 Tesseract: Heap out-of-bounds write/read in FullyConnected::Forward via layer/weight-matrix dimension mismatch
- CVE-2026-88049 Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch
- 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-2026-88051, ECHO-09e7-889a-f5d7, GHSA-88qp-4g94-3rf3, UBUNTU-CVE-2026-88051.