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Fencer Intel
high 7.8

CVE-2026-88053 json

Tesseract: Heap out-of-bounds write in Classify::ReadIntTemplates via unvalidated counts in crafted .traineddata

published 2mo ago modified last mo. also EUVD-2026-75630 , GHSA-rphx-x795-5qjv

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository tesseract-ocr/tesseract. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, Classify::ReadIntTemplates in src/classify/intproto.cpp reads NumClassPruners, NumClasses, and NumProtoSets from the TESSDATA_INTTEMP component of a crafted .traineddata file and uses those values as loop bounds without validating them against MAX_NUM_CLASS_PRUNERS, MAX_NUM_CLASSES, and MAX_NUM_PROTO_SETS. The loops store heap pointers into fixed-capacity ClassPruners and ProtoSets arrays in INT_TEMPLATES_STRUCT and INT_CLASS_STRUCT, so an oversized count causes heap out-of-bounds pointer writes during legacy-classifier initialization before OCR begins, resulting in heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.

Patch / fix

  • tesseract Ubuntu Pro 18.04 LTS 4.00~git2288-10f4998a-2ubuntu0.1~esm1
  • tesseract Ubuntu Pro 20.04 LTS 4.1.1-2ubuntu0.1~esm1
  • tesseract Ubuntu Pro 22.04 LTS 4.1.1-2.1ubuntu0.1~esm1
  • tesseract Ubuntu Pro 24.04 LTS 5.3.4-1ubuntu0.1~esm1
  • tesseract Ubuntu Pro 26.04 LTS 5.5.0-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2026-88053

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • tesseract-ocr openSUSE Leap 16.0 5.5.3-bp160.2.1
  • tesseract-ocr openSUSE Leap 16.0 5.5.3-bp160.1.1
  • tesseract-ocr openSUSE Tumbleweed 5.5.3-2.1

opensuse advisories openSUSE-RU-2026:22002-1openSUSE-SU-2026:21957-1openSUSE-SU-2026:11887-1

  • tesseract AlmaLinux 8 4.1.1-7.el8_10
  • tesseract AlmaLinux 10 5.3.4-11.el10_2

almalinux advisories ALSA-2026:95725ALSA-2026:95085

  • tesseract Rocky Linux 9 4.1.1-11.el9_8
  • tesseract Rocky Linux 8 4.1.1-7.el8_10
  • tesseract Rocky Linux 10 5.3.4-11.el10_2

rocky linux advisories RLSA-2026:98514RLSA-2026:95725RLSA-2026:95086RLSA-2026:95085

Is CVE-2026-88053 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-88053 updated cvss 8.4

tesseract: Tesseract: Heap out-of-bounds write leads to heap corruption via crafted data file

  • Red Hat Enterprise Linux AppStream (v. 8) tesseract 4.1.1-7.el8_10
    fixed: vendor fix RHSA-2026:95725
  • Red Hat Enterprise Linux AppStream (v. 9) tesseract 4.1.1-11.el9_8, tesseract 4.1.1-11.el9_9
    fixed: vendor fix RHSA-2026:95086
  • Red Hat Enterprise Linux AppStream (v. 10) tesseract 5.3.4-11.el10_2, tesseract 5.3.4-11.el10_3
    fixed: vendor fix RHSA-2026:95085
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) tesseract 4.1.1-2.el8_6.3
    fixed: vendor fix RHSA-2026:96239
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) tesseract 4.1.1-2.el8_8.3
    fixed: vendor fix RHSA-2026:96238
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) tesseract 4.1.1-2.el8_6.3
    fixed: vendor fix RHSA-2026:96239
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) tesseract 4.1.1-2.el8_8.3
    fixed: vendor fix RHSA-2026:96238
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) tesseract-devel 4.1.1-11.el9_8, tesseract-devel 4.1.1-11.el9_9, tesseract-debuginfo 4.1.1-11.el9_8, tesseract-debuginfo 4.1.1-11.el9_9, tesseract-debugsource 4.1.1-11.el9_8, tesseract-debugsource 4.1.1-11.el9_9, +2 more
    fixed: vendor fix RHSA-2026:95086
show 2 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) tesseract-devel 5.3.4-11.el10_2, tesseract-devel 5.3.4-11.el10_3, tesseract-debuginfo 5.3.4-11.el10_2, tesseract-debuginfo 5.3.4-11.el10_3, tesseract-debugsource 5.3.4-11.el10_2, tesseract-debugsource 5.3.4-11.el10_3, +2 more
    fixed: vendor fix RHSA-2026:95085
  • Red Hat Enterprise Linux CRB (v. 8) tesseract-devel 4.1.1-7.el8_10, tesseract-debuginfo 4.1.1-7.el8_10, tesseract-debugsource 4.1.1-7.el8_10
    fixed: vendor fix RHSA-2026:95725

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-rphx-x795-5qjv referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.6 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 8.6 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • tesseract-ocr tesseract

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of tesseract-ocr/tesseract published their own advisory on GitHub. Reviewed sources take precedence over it.