Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-88052

CVE-2026-88052HIGH

tesseract-ocr tesseract — Tesseract: Heap out-of-bounds write in UNICHARSET::load_via_fgets via count/insert desynchronization

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   N   R  U  H  H  H    7.8   .0018    7.2     —

AFFECTED
  Product    Versions    Fixed
  tesseract  <= 5.5.3 –  —

TIMELINE
  Sep 9   Reserved by GitHub_M
  Sep 10  Published (CNA: GitHub_M)
  Sep 16  EXPLOIT PUBLISHED — CVE-2026-88052 (tesseract-ocr tesseract). Public exploit reference added.

CWE-129, CWE-787 · CNA: GitHub_M · CVSS v3.1 · 2 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 9, 2026	Reserved	Reserved by GitHub_M
September 10, 2026	Published	Published (CNA: GitHub_M)
September 16, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-88052 (tesseract-ocr tesseract). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
tesseract-ocr	tesseract	—	<= 5.5.3	—

Weaknesses

CWE-129 · CWE-787

References (2)

https://github.com/tesseract-ocr/tesseract/commit/2d04d640db2e8c7e3bab2369d599343b5a8b8443 [Patch]
https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-2hm8-q5c7-c373 [Exploit, Mitigation, Vendor Advisory]

Authoritative record: CVE-2026-88052 at cve.org

Vendors: tesseract-ocr

Weaknesses: CWE-129 · CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-88052 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.