tesseract-ocr Tesseract up to 5.5.3 NORMPROTO normmatch.cpp Classify::ReadNormProtos stack-based overflow

Summaryinfo

A vulnerability described as critical has been identified in tesseract-ocr Tesseract up to 5.5.3. Affected is the function Classify::ReadNormProtos of the file src/classify/normmatch.cpp of the component NORMPROTO. Executing a manipulation can lead to stack-based overflow. This vulnerability appears as CVE-2026-88047. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as critical was found in tesseract-ocr Tesseract up to 5.5.3. This vulnerability affects the function Classify::ReadNormProtos of the file src/classify/normmatch.cpp of the component NORMPROTO. The manipulation with an unknown input leads to a stack-based overflow vulnerability. The CWE definition for the vulnerability is CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, Classify::ReadNormProtos in src/classify/normmatch.cpp parses the NORMPROTO component of a .traineddata file and uses std::istream::operator>>(char*) to extract a whitespace-delimited token into a fixed 61-byte stack buffer without setting a stream width. The 100-byte line buffer can carry a token of up to 99 characters, so a token longer than 60 characters writes up to 39 attacker-controlled bytes past the buffer during TessBaseAPI::Init of the legacy engine, causing stack corruption, denial of service, and potentially control-flow hijacking on affected standard-library implementations. Builds using Apple's libc++ C++20 bounded array overload are incidentally protected, while typical libstdc++ builds remain affected. No fixed release is available as of this review.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-88047 since 09/09/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/10/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• tesseract-ocr

Name

• Tesseract

Version

• 5.5.0
• 5.5.1
• 5.5.2
• 5.5.3

Website

• Product: https://github.com/tesseract-ocr/tesseract/

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