CVE-2026-88052

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, UNICHARSET::load via fgets in src/ccutil/unicharset.cpp trusts the declared unichar count as a loop bound and uses id as an unchecked index into the unichars vector. unichar insert backwards compatible can leave the vector unchanged for an empty, duplicate, or already-encodable representation, causing id to become larger than unichars.size(). Subsequent set * calls and the write to unichars[id].properties.enabled then write UNICHAR PROPERTIES beyond the vector during initialization in both the default LSTM and legacy engines, causing heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.