Log in Start free

Vulnerability · Published Sep 10, 2026 · Assigned by GitHub_M

CVE-2026-88050Tesseract: Out-of-bounds write in UnicharCompress via unvalidated recoder code values

Medium 6.9

In plain English

A medium-severity out-of-bounds write in tesseract from tesseract-ocr. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities).

Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.1%top 95.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, RecodedCharID::DeSerialize in src/ccutil/unicharcompress.h validates length_ but accepts negative code_ values from a crafted .traineddata recoder component. UnicharCompress::ComputeCodeRange in src/ccutil/unicharcompress.cpp can consequently produce code_range_ equal to zero, after which SetupDecoder indexes is_valid_start_ with the negative code on a size-zero vector. The resulting out-of-bounds bit write uses a large wrapped index and reliably causes a wild-address crash or allocation failure on the default LSTM engine. No fixed release is available as of this review.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12tesseractno fix listedDEBIAN-CVE-2026-88050
Debian:13tesseractno fix listedDEBIAN-CVE-2026-88050
Debian:14tesseractno fix listedDEBIAN-CVE-2026-88050
Ubuntu:26.10tesseractno fix listedUBUNTU-CVE-2026-88050

Affected products (as reported)

VendorProductVersions
tesseract-ocr tesseract <= 5.5.3

Weakness: CWE-787 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References