7.8High

Tesseract-Ocr Tesseract Ocr

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.

What this means for your business

  • It affects Tesseract-Ocr Tesseract Ocr. It matters if your company, or a supplier that handles your data, runs it.
  • Code showing how to exploit it has been published, but real attacks have not been confirmed.
  • An attacker can use it only with access to the machine itself, without a login, but only after tricking someone into an action such as opening a file or a link.
  • FIRST's prediction model gives it a 0.1% chance of attack attempts being seen in the next 30 days, ranking above 1% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Tesseract-Ocr Tesseract Ocr, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
7.8 (v3.1)
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness
CWE-129
Assigned by
security-advisories@github.com

Dates

Published
2026-09-10
Last modified
2026-09-16
Sources
NVD

Affected products

  • Tesseract-Ocr Tesseract Ocr- 5.5.3

As listed in the NVD configuration data. Not a statement about your estate.

References