CVE-2026-88053 Tesseract: Heap out-of-bounds write in Classify::ReadIntTemplates via unvalidated counts in crafted .traineddata
An attacker can cause heap corruption or potential code execution in Tesseract by providing a crafted .traineddata file with unvalidated counts.
- 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-2026-88053?
CVE-2026-88053 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, Classify::ReadIntTemplates in src/classify/intproto.cpp reads NumClassPruners, NumClasses, and NumProtoSets from the TESSDATA_INTTEMP component of a crafted .traineddata file and uses those values as loop bounds without validating them against MAX_NUM_CLASS_PRUNERS, MAX_NUM_CLASSES, and MAX_NUM_PROTO_SETS. The loops store heap pointers into fixed-capacity ClassPruners and ProtoSets arrays in INT_TEMPLATES_STRUCT and INT_CLASS_STRUCT, so an oversized count causes heap out-of-bounds pointer writes during legacy-classifier initialization before OCR begins, resulting in 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-2026-88053?
It affects 1 product.
Linux distribution packages (1)
tesseract-ocr openSUSE:Leap 16.0 | All versions | 5.5.3-bp160.2.1 |
Products include Tesseract-Ocr Tesseract Ocr.
How do I fix CVE-2026-88053?
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-2026-88053 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-88053 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-2026-88051 Tesseract: Heap out-of-bounds write in GenericVector<T>::read due to independent reserved/size_used_ fields
- CVE-2026-88052 Tesseract: Heap out-of-bounds write in UNICHARSET::load_via_fgets via count/insert desynchronization
Sources
Also known as DEBIAN-CVE-2026-88053, ECHO-8957-f2f8-e53c, GHSA-rphx-x795-5qjv, UBUNTU-CVE-2026-88053, openSUSE-RU-2026:22002-1.