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Fencer Vulns
medium 5.5

CVE-2026-88049 json

Tesseract: Heap out-of-bounds write in LSTM::Forward via na_/gate-matrix dimension mismatch

published 2026-09-10 1 mo ago modified 2026-09-14 55 d ago also EUVD-2026-75592

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

Tesseract is an open source OCR engine. In version 5.5.3 and earlier, prior .traineddata hardening added bounds checks to NetworkIO::CopyTimeStepGeneral and NetworkIO::Randomize in src/lstm/networkio.cpp but left NetworkIO::WriteTimeStepPart and NetworkIO::AddTimeStepPart unchecked. In LSTM::Forward in src/lstm/lstm.cpp, source_ is sized from the independently deserialized na_ field while the WriteTimeStepPart count is ns_, which comes from the CI gate WeightMatrix dim1() value. A crafted NT_LSTM layer can make ns_ much larger than na_, causing a heap out-of-bounds write during the first recognition step on the default LSTM engine and 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-2026-88049

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

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

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

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-2026-88049 updated cvss 7.8

tesseract: Tesseract: Heap out-of-bounds write allows arbitrary code execution or denial of service

  • 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
    fixed: vendor fix RHSA-2026:95086
  • Red Hat Enterprise Linux AppStream (v. 10) tesseract 5.3.4-11.el10_2
    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-debuginfo 4.1.1-11.el9_8, tesseract-debugsource 4.1.1-11.el9_8, tesseract-tools-debuginfo 4.1.1-11.el9_8
    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-debuginfo 5.3.4-11.el10_2, tesseract-debugsource 5.3.4-11.el10_2, tesseract-tools-debuginfo 5.3.4-11.el10_2
    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
59 d ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/tesseract-ocr/tesseract/security/advisories/GHSA-jgq8-pprg-vc68 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 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • tesseract-ocr tesseract

Classification

Weakness

References

Sources

Fencer Vulns 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.